Ship propulsion systems

Abstract

The present invention provides a ship propulsion system that can more effectively suppress the humping of the hull and stabilize the behavior of the ship. [Solution] The ship's propulsion system comprises a drive source and a propulsion unit that generates thrust by power transmitted from the drive source, a propulsion machine provided on the hull, a trim angle adjustment unit that adjusts the trim angle of the propulsion machine with respect to the hull, and a control unit that controls the trim angle adjustment unit, wherein the control unit is capable of performing hump control, which involves adjusting the trim angle at the trim angle adjustment unit to suppress the pitch tilt of the hull, and is capable of performing hump control when the ship's speed is within a preset speed range.

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 in order to improve the stability, acceleration performance, maximum speed, fuel efficiency and the like of a marine vessel during navigation. For example, when the bow is greatly lifted relative to the stern and the pitch angle of the hull with respect to the horizontal plane increases, a so-called hump state occurs, which may impair the forward visibility of the marine vessel.

[0003] For example, Patent Document 1 discloses that when the pitch angle of the hull with respect to the horizontal plane exceeds a set value, the trim angle of the propulsion unit is reduced to suppress the hump state of the hull.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0005] However, if the trim angle of the propulsion unit is reduced when the pitch angle of the hull exceeds the set value as in the above conventional technique, the hump state of the hull may not be sufficiently suppressed depending on the navigation state of the marine vessel. The present invention has been made in view of the above circumstances, and an object thereof is to provide a marine vessel propulsion system capable of more effectively suppressing the hump state of the hull and stabilizing the behavior of the hull.

Means for Solving the Problem

[0006] (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, and includes a propulsion machine provided on the hull, A trim angle adjustment unit for adjusting the trim angle of the propulsion unit 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 pitch direction, hump control is possible, which adjusts the trim angle at the trim angle adjustment unit. The hump control can be executed when the ship's speed is within a preset speed range.

[0007] (2) In the propulsion system of a ship relating to the embodiment of (1) above, The control unit, When the ship's speed reaches a predetermined first threshold during acceleration, the hump control can be executed. While the hump control is being performed during the acceleration of the hull, if the ship speed becomes greater than or equal to a second threshold, which is greater than the first threshold, the execution of the hump control may be stopped.

[0008] (3) In the propulsion system of a ship relating to the embodiment of (2) above, The control unit, When the hull is accelerating, if the pitch angle of the hull becomes equal to or greater than a preset first reference pitch angle, the hump control can be executed. When the hull is decelerating, if the pitch angle becomes smaller than the second reference pitch angle, which is smaller than the first reference pitch angle, the execution of the hump control may be stopped.

[0009] (4) In the propulsion system of a ship relating to the embodiment of (2) above, The control unit, During acceleration, the hump control may be enabled when the ship speed is below the first threshold and the lever opening of the propulsion system is equal to or greater than a preset reference opening.

[0010] (5) In a propulsion system for a ship relating to the embodiment of (2) or (4) above, The control unit, When the ship's speed is reduced during the deceleration of the hull, the hump control can be executed if the ship's speed falls below a third threshold, which is lower than the second threshold. While the hump control is being performed during the deceleration of the hull, if the ship speed falls below the fourth threshold, which is lower than the first threshold, the execution of the hump control may be stopped.

[0011] (6) In the propulsion system of a ship relating to the embodiment of (5) above, The control unit, During deceleration, the hump control may be enabled when the ship speed is less than the second threshold and greater than the third threshold, and the pitch angle of the ship is greater than or equal to a preset third reference pitch angle.

[0012] (7) In a ship propulsion system relating to any one of the embodiments described in (1) to (6) above, The control unit, The hump control may be made executable when it is determined that the ship speed is within the speed range and the ship is turning.

[0013] (8) In a ship propulsion system relating to any one of the embodiments described in (1) to (7) above, 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 operation unit while the hump control is being performed, the execution of the hump control may be stopped.

[0014] (9) In a ship propulsion system relating to the embodiment of (8) above, The control unit, When the execution of the hump control has been stopped in response to an operation input from the trim angle control unit, the system may be made capable of executing the hump control again if a preset recovery condition is met. Effects of the Invention

[0015] According to the aspect (1), the hump control can be executed when the ship speed of the hull is within a preset speed region. Thereby, the hump state of the hull can be suppressed by executing the hump control at an appropriate timing according to the ship speed. Therefore, the hump state of the hull can be more effectively suppressed, and the behavior of the hull can be stabilized.

[0016] According to the aspect (2), during acceleration of the hull, the hump control is executed when the ship speed is equal to or higher than the first threshold value, so that the behavior of the hull can be stabilized in the speed range where the hump state is likely to occur. In addition, in a state where the hump control is being executed during acceleration of the hull, when the ship speed becomes equal to or higher than a second threshold value that is larger than the first threshold value, the execution of the hump control is stopped, so that the hump control can be performed in the speed range where it is effective.

[0017] According to the aspect (3), during acceleration, the hump control can be executed when the pitch angle of the hull is equal to or greater than the first reference pitch angle, and during deceleration, the execution of the hump control is stopped when the pitch angle becomes smaller than a second reference pitch angle that is smaller than the first reference pitch angle. This suppresses frequent intermittent activation and deactivation of the hump control when the pitch angle fluctuates around the first reference pitch angle and the second reference pitch angle.

[0018] According to the aspect (4), during acceleration, even if the ship speed is less than the first threshold value, the hump control can be executed when the lever opening of the propulsion device is equal to or greater than the reference opening. Thereby, even in a state where the ship speed is low, the behavior of the hull can be stabilized by executing the hump control when the lever opening is large and the pitch angle is likely to increase.

[0019] According to embodiment (5), when the ship is decelerating, hump control is enabled when the ship speed is below the third threshold, which is lower than the second threshold. When hump control is being performed during deceleration, the execution of hump control is stopped when the ship speed falls below the fourth threshold, which is lower than the first threshold. This stabilizes the ship's behavior even during deceleration. Furthermore, since the third and fourth thresholds, which are the thresholds during deceleration, are lower than the second and first thresholds, which are the thresholds during acceleration, frequent interruptions in hump control are suppressed when the ship speed is fluctuating around the second and first thresholds.

[0020] According to the embodiment of (6), when decelerating, hump control can be performed when the ship speed is less than the second threshold but greater than the third threshold, and is below the fifth threshold, and the pitch angle of the ship is greater than or equal to the third reference pitch angle. This makes it possible to stabilize the ship's behavior when the pitch angle of the ship is large, even when the ship speed does not decrease to the third threshold during deceleration.

[0021] According to embodiment (7), when the ship speed is within a preset speed range, hump control is performed when it is determined that the ship is turning. This makes it possible to stabilize the ship's behavior even while turning.

[0022] According to embodiment (8), if an operation input is received from the trim angle control unit while hump control is being performed, the execution of hump control is stopped. This prevents the operator from feeling any discomfort when the trim angle is manually operated by the ship's operator by stopping the execution of hump control.

[0023] According to embodiment (9), when the execution of hump control is stopped after receiving an operation input from the trim angle operation unit, the system is made capable of executing hump control when a preset return condition is met. This allows the system to transition to a standby state in which hump control can be executed after the execution of heel control is stopped by the operator of the vessel, when a preset return condition is met. [Brief explanation of the drawing]

[0024] [Figure 1] This is a plan view of a vessel according to this embodiment. [Figure 2] This is a functional block diagram of the propulsion system of the above-mentioned vessel. [Figure 3] A side view of the propulsion system's thruster shown above. [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 trim support angle settings for trim support control, heel control, and hump control performed according to 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 diagram shows the above vessel performing hump control. [Figure 10] This figure shows examples of ship speed thresholds in hump control. [Figure 11] This flowchart shows how to perform hump control when trim support control is being executed. [Figure 12] This is a timing chart illustrating an example of the operation of the above propulsion system. [Figure 13] This timing chart shows another example of the operation of the above propulsion system. [Modes for carrying out the invention]

[0025] 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 of the vessel 1. The center line CL extends in the front-rear direction at the center position in the left-right direction (width direction) of the vessel 1.

[0026] 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).

[0027] (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.

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 trim angle θt when the thruster 3 is rotated to its most negative position is defined as the lower limit of the trim angle. 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).

[0035] (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.

[0036] 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.

[0037] 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: 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.

[0038] 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).

[0039] 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, 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.

[0040] (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 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. Based on the position of the thrust input unit 72, which is, for example, a throttle lever that indicates the lever opening, the position sensor 61 detects the lever opening of the thruster 3. The position sensor 61 outputs a detection signal based on the position of the thrust input unit 72 to the control unit 8.

[0041] As shown in Figure 2, 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.

[0042] 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.

[0043] 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 also detects the tilt of the hull 2 ​​in the pitch direction, i.e., the pitch angle θp. The inertial sensor 64 outputs detection signals based on the detected tilt of the hull 2 ​​in the roll and pitch directions to the control unit 8.

[0044] The trim operation sensor 65 detects whether or not an 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.

[0045] 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.

[0046] 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.

[0047] (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.

[0048] The control unit 8 includes a storage unit 80, an acquisition unit 81, a determination unit 82, and a drive processing unit 83.

[0049] 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.

[0050] 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.

[0051] (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.

[0052] 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, in the 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 advance. 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).

[0053] 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.

[0054] (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 that the preset conditions are 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.

[0055] 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.

[0056] 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.

[0057] Figure 7 shows the state of heel control when the ship is tilting to port. Figure 8 shows the state of heel control when the ship 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.

[0058] (Hump control) Figure 9 shows a ship performing hump control. If the determination unit 82 determines that the preset conditions are met, the drive processing unit 83 executes hump control. As shown in Figure 9, hump control is performed to suppress excessive lift of the bow 2a when the bow 2a is significantly lifted relative to the stern 2b and the pitch angle θp is large. 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.

[0059] Figure 10 shows examples of ship speed thresholds in hump control. As will be described in detail later, the drive processing unit 83 enables hump control when the ship speed V of the hull 2 ​​is within a preset speed range. Specifically, as shown in Figure 10, the drive processing unit 83 executes hump control when the ship speed V is within a set speed range if it is greater than or equal to a preset first threshold V1 and less than a preset second threshold V2 during the acceleration of the hull 2. The drive processing unit 83 enables hump control when the ship speed V becomes greater than or equal to a preset first threshold V1 during the acceleration of the hull 2. The drive processing unit 83 stops executing hump control when it is executing hump control during the acceleration of the hull 2 ​​and the ship speed V becomes greater than or equal to a second threshold V2 which is greater than the first threshold V1. Furthermore, the drive processing unit 83 enables hump control when the ship speed V is less than the first threshold V1 during acceleration of the hull 2, and the lever opening of the propulsion unit 3 is equal to or greater than a preset reference opening.

[0060] Furthermore, when the hull 2 ​​is decelerating, the drive processing unit 83 determines that the ship speed V is within the set speed range and executes hump control when the ship speed V is higher than a preset fourth threshold V4 and less than or equal to the third threshold V3. The drive processing unit 83 enables hump control when the ship speed V is less than or equal to the third threshold V3, which is less than the second threshold V2, during the deceleration of the hull 2. The drive processing unit 83 stops executing hump control when it is executing hump control during the deceleration of the hull 2 ​​and the ship speed V is less than or equal to the fourth threshold V4, which is less than the first threshold V1. Furthermore, the drive processing unit 83 enables hump control when the ship speed V is less than or equal to the fifth threshold V5, which is less than the second threshold V2 and greater than the third threshold V3, and the pitch angle θp of the ship 2 is greater than or equal to a preset third reference pitch angle, during the deceleration of the hull 2.

[0061] Furthermore, the drive processing unit 83 may be configured to perform hump control when it is determined that the ship speed V is within the set speed range and the hull 2 ​​is turning. Furthermore, if the drive processing unit 83 receives an operation input from the trim angle operation unit 73 while hump control is being performed, it stops the execution of hump control.

[0062] (Bogen control) 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 by 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.

[0063] (Control method for the propulsion system) Next, the operation method of the propulsion system will be explained. The processes described below are executed repeatedly, for example, at a predetermined control cycle (e.g., several tens of milliseconds). Figure 11 is a flowchart showing the flow of the control method for the propulsion system. The flowchart shown in Figure 11 illustrates the processing flow when performing hump control, which is part of the control of the propulsion system 20 executed by the control unit 8. As shown in Figure 11, in step S11, the control unit 8 acquires the ship speed detection result from the ship speed sensor 62 using the acquisition unit 81. In step S11, in order to detect a change in ship speed, the control unit 8 acquires the ship speed detection result multiple times with a predetermined control cycle interval.

[0064] In step S12, the control unit 8 determines, based on the detection result of the ship speed sensor 62, whether the ship speed V of the hull 2 ​​is within a preset speed range. In this case, the control unit 8 determines that the ship speed V is within the set speed range when the ship speed V is greater than or equal to a preset first threshold V1 and less than a preset second threshold V2 during the acceleration of the ship hull 2. When the hull 2 ​​is decelerating, the control unit 8 determines that the ship speed V is within the set speed range if the ship speed V is higher than a preset fourth threshold V4 and less than or equal to the third threshold V3, and executes hump control. Here, the fourth threshold V4 is set, for example, 5 to 10 km / h lower than the first threshold V1. The third threshold V3 is set, for example, 5 to 10 km / h lower than the second threshold V2.

[0065] If the ship speed V is outside the set speed range and the result of the determination in step S12 is "No", proceed to step S13, which will be described later.

[0066] (If the ship speed is determined to be within the set range) If the ship speed V is within the set speed range and the result of the determination in step S12 is "Yes", the system skips to step S15, and the control unit 8 enters a standby state where it can perform hump control. In the following step S16, the control unit 8 determines whether the conditions for executing hump control when the ship speed V is within the set speed range are met.

[0067] Examples of conditions for executing hump control when the ship speed V is within the set speed range include the following conditions a1) and a2). Condition a1) The detected pitch angle θp acquired by the inertial sensor 64 is greater than the preset first reference pitch angle. Condition a2) Based on the actual steering angle detected by the actual steering angle sensor 67, it is determined that the hull 2 ​​is turning. If the ship speed V is within the set speed range, in step S16, the control unit 8 determines that the hump control execution condition is satisfied if at least one of conditions a1) and a2) is satisfied.

[0068] If the result of the determination in step S16 is "No", the process ends, a predetermined control cycle is observed, and the process from step S11 is repeated. If the result of step S16 is "Yes", proceed to step S17.

[0069] (If the ship speed is determined to be outside the set range) If the ship speed V is outside the set speed range and the result of the determination in step S12 is "No", then in step S13, the control unit 8 determines whether or not the acceleration exception condition is satisfied. Examples of exceptions during acceleration include the following conditions b1) to b3). Condition b1) The hull 2 ​​is accelerating. Condition b2) The ship speed V is less than the first threshold V1. Condition b3) The lever opening of the thruster 3, as obtained by the position sensor 61, is greater than a preset reference opening. If the ship speed V is outside the set speed range and all of conditions b1) to b3) are satisfied, the control unit 8 determines in step S13 that the acceleration exception condition is satisfied.

[0070] If the result of step S13 is "Yes", the process skips to step S15, and the control unit 8 enters a standby state where it can perform hump control. In the following step S16, the control unit 8 determines whether the conditions for executing hump control are met when the acceleration exception conditions are satisfied.

[0071] When the ship speed V is outside the set speed range and the acceleration exception condition is satisfied in step S13, the following conditions c1) to c3) are examples of conditions for executing hump control. Condition c1) The lever opening of the thruster 3, as obtained by the position sensor 61, is greater than the preset first lever opening. Condition c2) The detected pitch angle θp acquired by the inertial sensor 64 is greater than the preset reference pitch angle. Condition c3) Based on the actual rudder angle detected by the actual rudder angle sensor 67, it is determined that the hull 2 ​​is turning. Here, the first lever opening may be the same value as the reference opening described above, or it may be a value slightly larger than the reference opening. If the ship speed V is outside the set speed range and the acceleration exception condition is satisfied, in step S16, if at least one of conditions c1) to c3) is satisfied, the control unit 8 determines that the hump control execution condition is satisfied.

[0072] If the result of the determination in step S16 is "No", the process ends, a predetermined control cycle is observed, and the process from step S11 is repeated. If the result of step S16 is "Yes", proceed to step S17.

[0073] (If the ship speed is determined to be outside the set range) If the ship speed V is outside the set speed range and the result of the determination in step S13 is "No", then in step S14, the control unit 8 determines whether or not the deceleration exception condition is satisfied. Examples of exceptions during deceleration include the following conditions d1) and d2). Condition d1) The hull 2 ​​is decelerating. Condition d2) The ship speed V is between the third threshold V3 and the fifth threshold V5. If the ship speed V is outside the set speed range and all conditions d1) and d2) are satisfied, the control unit 8 determines that the deceleration exception condition is satisfied.

[0074] If the result of the judgment in step S14 is "No", the process ends, a predetermined control cycle is observed, and the process from step S11 is repeated. If the result of the determination in step S14 is "Yes", the process proceeds to step S15, and the control unit 8 is put into a standby state where it can perform hump control. In the following step S16, the control unit 8 determines whether the conditions for executing hump control are met when the deceleration exception conditions are satisfied.

[0075] For example, the following condition e1) is an example of a condition for executing hump control when the ship speed V is outside the set speed range and the deceleration exception condition is satisfied. Condition e1) The detected pitch angle θp acquired by the inertial sensor 64 is greater than the preset third reference pitch angle. Here, the third reference pitch angle may be the same value as the first reference pitch angle, or it may be slightly larger than the first reference pitch angle. If the ship speed V is outside the set speed range and the deceleration exception condition is met, in step S16, if condition e1) is met, the control unit 8 determines that the hump control execution condition is met.

[0076] If the result of the determination in step S16 is "No", the process ends, a predetermined control cycle is observed, and the process from step S11 is repeated. If the result of step S16 is "Yes", proceed to step S17.

[0077] (Execution of hump control) In step S17, the control unit 8 performs hump control. In this case, the control unit 8 reduces the trim angle θt of all thrusters 3 to the lower limit of the trim angle.

[0078] After starting the execution of hump control in step S17, the control unit 8 determines in step S18 whether a predetermined stop condition for stopping the hump control has been met during the execution of the hump control. In this embodiment, the following condition g1) is an example of a predetermined stop condition for stopping the hump control. Condition g1) When the operator receives an input from the trim angle control unit 73. If condition g1) is satisfied, the control unit 8 determines that the stop condition for stopping the hump control has been satisfied.

[0079] If the result of the determination in step S18 is "No", the process is terminated, a predetermined control cycle is observed, and step S11 is repeated. If the result of the determination in step S18 is "Yes", the process proceeds to step S19, and the execution of the hump control is stopped.

[0080] If the execution of hump control is stopped in step S19, then in step S20, the control unit 8 determines whether or not a preset recovery condition has been met at predetermined control cycles. Here, the following condition h1) is an example of a recovery condition. Condition h1): The ship speed V has fallen outside the set range.

[0081] If condition h1) is met, the control unit 8 may determine that the return condition has been met, return to step S11, and repeat the process to re-execute the hump control.

[0082] Figure 12 is a timing chart showing an example of the operation of the propulsion system. In Figure 12, for each of the "Ship Speed ​​Determination Flag," "Hump State Determination Flag," and "Hump Control Implementation Determination Flag," "0" indicates that the determination result in the control unit 8 is "No," and "1" indicates that the determination result in the control unit 8 is "Yes." As shown in Figure 12, for example, the lever opening increases due to the operation of the thrust input unit 72 by the helmsman, and the ship speed V increases. As the ship speed V increases, when the pitch angle θp exceeds the first reference pitch angle (time t1), the hump state determination flag changes from "0" to "1", and hump control is initiated. At this time, the control unit 8 changes the trim operation determination flag from "0" to "1" and performs a trim operation.

[0083] Subsequently, when the increase in pitch angle θp subsides due to the execution of hump control, and the pitch angle θp decreases, and the pitch angle θp becomes less than or equal to the second reference pitch angle which is smaller than the first reference pitch angle (time t2), the hump determination flag changes from "1" to "0". At this point, the control unit 8 changes the trim operation determination flag from "1" to "0" and stops the execution of hump control.

[0084] Figure 13 is a timing chart showing another example of the propulsion system's operation. As shown in Figure 13, for example, when the lever opening is rapidly increased by the operator's operation of the thrust input unit 72, the above conditions b1) to b3) are met (time t11), and the hump control is started, so the hump state determination flag changes from "0" to "1", and the trim operation determination flag changes from "0" to "1".

[0085] Subsequently, when the trim angle θt of thruster 3 decreases to the lower limit of the trim angle due to the execution of hump control (time t12), the trim operation judgment flag changes from "1" to "0" because the trim angle θt cannot be reduced any further for the sake of hump control, and the trim operation stops.

[0086] Subsequently, the hump control is implemented, causing the increase in the pitch angle θp to subside and the pitch angle θp to decrease. When the ship speed V increases further and exceeds the second threshold V2 (time t13), the hump judgment flag changes from "1" to "0", and hump control ends. Then, the control unit 8 changes the trim operation judgment flag from "0" to "1", and the trim operation returns to normal control.

[0087] Thus, the propulsion system 20 of this embodiment is capable of performing hump control when the ship speed V of the hull 2 ​​is within a preset speed range. By performing hump control at an appropriate timing according to the ship speed V, the hump state of the hull 2 ​​can be suppressed. Therefore, the hump state of the hull can be suppressed more effectively, and the behavior of the hull can be stabilized.

[0088] Furthermore, in this embodiment, the propulsion system 20 can stabilize the behavior of the hull 2 ​​in the speed range where a hump is likely to occur by executing hump control when the ship speed V is greater than or equal to the first threshold V1 and less than the second threshold V2 during the acceleration of the hull 2. Also, when hump control is being executed during the acceleration of the hull 2, if the ship speed V becomes greater than or equal to the second threshold V2, the execution of hump control is stopped, allowing hump control to be performed in the speed range where hump control is effective.

[0089] Furthermore, the propulsion system 20 of this embodiment enables hump control when the pitch angle θp of the hull 2 ​​becomes equal to or greater than the first reference pitch angle during acceleration, and stops the execution of hump control when the pitch angle θp becomes smaller than the second reference pitch angle, which is smaller than the first reference pitch angle, during deceleration. This suppresses frequent intermittent hump control when the pitch angle is fluctuating around the first and second reference pitch angles.

[0090] Furthermore, the propulsion system 20 of this embodiment can perform hump control during acceleration even when the ship speed V is below the first threshold V1, as long as the lever opening of the propulsion unit 3 is greater than or equal to the reference opening. This allows for stabilization of the ship's behavior by performing hump control when the lever opening is large and the pitch angle θp tends to be large, even when the ship speed V is low.

[0091] Furthermore, in this embodiment, the propulsion system 20 enables hump control when the ship speed V is less than or equal to the third threshold V3, which is smaller than the second threshold V2, during deceleration of the hull 2. When hump control is being performed during deceleration, the system stops the execution of hump control when the ship speed V falls below the fourth threshold V4, which is smaller than the first threshold V1. This ensures that the behavior of the hull 2 ​​is stabilized even during deceleration. In addition, since the third threshold V3 and fourth threshold V4, which are the thresholds during deceleration, are smaller than the second threshold V2 and first threshold V1, which are the thresholds during acceleration, frequent interruptions in hump control are suppressed when the ship speed V is fluctuating around the second threshold V2 and first threshold V1.

[0092] Furthermore, the propulsion system 20 of this embodiment enables hump control when, during deceleration, the ship speed V is greater than or equal to the fifth threshold V5 (which is greater than the third threshold V3), and the pitch angle θp of the hull 2 ​​is greater than or equal to the third reference pitch angle. This allows for stabilization of the hull 2's behavior when the pitch angle θp of the hull 2 ​​is large, even if the ship speed V does not decrease to the third threshold V3 during deceleration.

[0093] Furthermore, the propulsion system 20 of this embodiment performs hump control when it is determined that the hull 2 ​​is turning, provided that the ship speed V is within a preset speed range. This stabilizes the behavior of the hull 2 ​​even while turning.

[0094] Furthermore, in this embodiment, if the propulsion system 20 receives an input from the trim angle control unit 73 while hump control is being performed, it stops the execution of hump control. This prevents the operator of the vessel 1 from feeling any discomfort when the trim angle is manually adjusted by the operator of the vessel 1, by stopping the execution of hump control.

[0095] Furthermore, the propulsion system 20 of this embodiment, while in a state where it has stopped the execution of hump control after receiving an operation input from the trim angle operation unit 73, will be able to perform hump control when a preset return condition is met. This allows the system to transition to a standby state where hump control can be performed after the execution of heel control is stopped by the operator of the vessel 1, and the preset return condition is met.

[0096] 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, various conditions for implementing hump control were illustrated, but these conditions can be changed as appropriate.

[0097] Furthermore, in the above embodiment, one thruster 3 is provided on each of the left and right sides, but multiple thrusters may be provided on each of the left and right sides, or one may be provided in the center. 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]

[0098] 1 ship 2 hull 3 Propulsion machine 3a Right propulsion machine (propulsion machine) 3b Left propulsion machine (propulsion machine) 8 Control Unit 20 Propulsion System 32 Power source 34 Promotion Department 45 Trim angle adjustment section 73 Trim angle control section V Ship speed V1 First threshold V2 Second threshold V3 Third threshold V4 Fourth threshold V5 Fifth threshold

Claims

1. A propulsion system provided on the hull has a drive source and a propulsion unit that generates thrust by power transmitted from the drive source, A trim angle adjustment unit for adjusting the trim angle of the propulsion unit 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 pitch direction, hump control is possible, which adjusts the trim angle at the trim angle adjustment unit. The hump control can be executed when the ship's speed is within a preset speed range. A ship's propulsion system.

2. The control unit, When the ship's speed reaches a predetermined first threshold during acceleration, the hump control can be executed. When the hump control is being performed during the acceleration of the hull, if the ship speed becomes greater than or equal to a second threshold which is greater than the first threshold, the execution of the hump control is stopped. The propulsion system for a ship according to claim 1.

3. The control unit, When the hull is accelerating, if the pitch angle of the hull becomes equal to or greater than a preset first reference pitch angle, the hump control can be executed. When the hull is decelerating, if the hump control becomes smaller than the second reference pitch angle which is smaller than the first reference pitch angle, the execution of the hump control is stopped. The propulsion system for a ship according to claim 1.

4. The control unit, During acceleration, the hump control can be executed when the ship speed is below the first threshold and the lever opening of the propulsion system is equal to or greater than a preset reference opening. The propulsion system for a ship according to claim 2.

5. The control unit, When the ship's speed is reduced during the deceleration of the hull, the hump control can be executed if the ship's speed falls below a third threshold, which is lower than the second threshold. When the hump control is being performed during the deceleration of the hull, if the ship speed falls below the fourth threshold, which is lower than the first threshold, the execution of the hump control is stopped. A ship propulsion system according to claim 2 or 4.

6. The control unit, During deceleration, the hump control can be executed when the ship speed is less than the second threshold and greater than the third threshold, which is less than or equal to the fifth threshold, and the pitch angle of the ship is greater than or equal to a preset third reference pitch angle. The propulsion system for a ship according to claim 5.

7. The control unit, The hump control can be executed when it is determined that the ship speed is within the speed range and the ship is turning. A ship propulsion system according to claim 1 or 2.

8. 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 hump control is being performed, the execution of the hump control is stopped. A ship propulsion system according to claim 1 or 2.

9. The control unit, When the execution of the hump control has been stopped in response to an operation input from the trim angle control unit, and a preset recovery condition is met, the system will be set to enable the execution of the hump control. The propulsion system for a ship according to claim 8.

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