Propulsion system of boat

Abstract

A propulsion system of a boat according to the present disclosure includes: at least a first propulsion device and a second propulsion device that are provided side by side in a horizontal direction on a hull; and a controller configured to control dynamic power of each the first propulsion device and the second propulsion device and a direction of the dynamic power. During the bogen control, the controller calculates a first reference angle around a yaw direction with respect to a reference position for the direction of the dynamic power of the first propulsion device based on a thrust instruction value given to the hull and a second reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the second propulsion device based on the thrust instruction value given to the hull. Upon receipt of a steering instruction, the controller calculates a first steering command value based on a steering instruction value and the first reference angle, and also calculates a second steering command value based on the steering instruction value and the second reference angle. The controller controls the direction of the dynamic power of the first propulsion device, based on the first steering value, and also controls the direction of the dynamic power of the second propulsion device, based on the second steering command value.

Description

BACKGROUND OF THE INVENTIONField of the Invention

[0001] The present disclosure relates to a propulsion system of a boat.Description of Related Art

[0002] In recent years, efforts to provide access to sustainable transportation systems in consideration of vulnerable people among traffic participants are becoming active. In order to develop a sustainable transportation system, research and development for further improving traffic safety and convenience through, for example, driving support for boats are in progress. As a type of the driving support for boats, for example, Patent Document 1 (Japanese Patent No. 4673187) discloses so-called bogen control as a constitution for navigating a boat in a straight advancing direction at a very slow speed. The bogen control denotes control of causing a left propulsion device to rotate clockwise and a right propulsion device to rotate counterclockwise to arrange the left and right propulsion devices in a letter V shape when the entirety of the boat is viewed in a plan. The bogen control may be referred to as V-shaped control.SUMMARY OF THE INVENTION

[0003] In the related art, however, there is still room for improvement in response performance at the time of making a turn, when changing the course of the boat during the boben control.

[0004] The present disclosure provides a propulsion system of a boat capable of improving response performance at the time of making a turn. The present disclosure contributes to development of a sustainable transportation system, accordingly.

[0005] In order to solve the above-described problems, the present disclosure adopts the following aspects.

[0006] (1) A propulsion system of a boat according to one aspect of the present disclosure, includes: at least a first propulsion device and a second propulsion device, which are provided side by side in a horizontal direction on a hull; and a controller including at least a processor and a memory, the controller being configured to control dynamic power of each the first propulsion device and the second propulsion device and a direction of the dynamic power, in which the controller sets directions of the dynamic power of the first propulsion device and the dynamic power of the second propulsion device to be opposite to each other while being inclined around a yaw direction with respect to a reference position, when the hull moves either forward or rearward, and conducts bogen control of applying thrust to the hull, and during the bogen control, the controller calculates a first reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the first propulsion device based on a thrust instruction value given to the hull and a second reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the second propulsion device based on the thrust instruction value given to the hull, and upon receipt of a steering instruction, the controller calculates a first steering command value based on the steering instruction value and the first reference angle, and also calculates a second steering command value based on the steering instruction value and the second reference angle, and the controller controls the direction of the dynamic power of the first propulsion device, based on the first steering command value, and also controls the direction of the dynamic power of the second propulsion device, based on the second steering command value.

[0007] (2) In the propulsion system of the boat according to the above (1), the reference position is preferably a position in a state in which the directions of the dynamic power of the first propulsion device and the second propulsion device are parallel to a front-rear direction of the hull.

[0008] (3) In the propulsion system of the boat according to the above (2), in a case where the thrust instruction value is preferably equal to or larger than a thrust threshold, the controller sets each the first reference angle and the second reference angle to 0 degrees for the hull to move either forward or rearward.

[0009] (4) In the propulsion system of the boat according to the above (2) or (3), in a case where a boat speed is higher than a boat speed threshold, the controller preferably sets each the first reference angle and the second reference angle to 0 degrees for the hull to move either forward or rearward.

[0010] (5) In the propulsion system of the boat according to one of the above (1) to (4), during the bogen control, the controller preferably decreases the first reference angle and the second reference angle, as the thrust instruction value increases.

[0011] (6) In the propulsion system of the boat according to one of the above (1) to (5), a maximum value of the first reference angle is preferably a maximum angle of the direction of the dynamic power of the first propulsion device, and a maximum value of the second reference angle is preferably a maximum angle of the direction of the dynamic power of the second propulsion device.

[0012] (7) In the propulsion system of the boat according to the above (2) or (3), when the shift position is switched to the neutral position from the forward position, the controller preferably continues the bogen control.

[0013] (8) In the propulsion system of the boat according to the above (7), when the shift position is switched to a reverse position from the neutral position, the controller preferably sets each the first reference angle and the second reference angle to 0 degrees.

[0014] (9) In the propulsion system of the boat according to one of the above (1) to (8), out of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, and out of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value, during the bogen control, the controller preferably sets a change amount of the outer command value relative to a change amount of the steering instruction value to be larger than a change amount of the inner command value relative to the change amount of the steering instruction value.

[0015] (10) In the propulsion system of the boat according to one of the above (1) to (9), during the bogen control, as the steering instruction value increases on one side of a turning direction, the controller preferably either maintains or increases a steering command value of a propulsion device located on one side with respect to a steering reference angle, out of the first propulsion device and the second propulsion device, and preferably increases a steering command value of a propulsion device located on the other side with respect to the steering reference angle.

[0016] (11) In the propulsion system of the boat according to the above (4), out of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, and out of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value, during the bogen control, as the thrust instruction value increases, the controller preferably decreases a change amount of the outer command value relative to a change amount of the steering instruction value.

[0017] (12) In the propulsion system of the boat according to one of the above (1) to (11), out of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, and out of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value, during the bogen control, the controller preferably increases a change amount of the outer command value relative to a change amount of the steering instruction value, and preferably decreases a change amount of the inner command value relative to the change amount of the steering instruction value, as compared with a normal operation mode in which the first reference angle and the second reference angle are each set to 0 degrees.

[0018] According to the above aspects, response performance at the time of making a turn can be improved.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a plan view of a boat according to one embodiment;

[0020] FIG. 2 is a side view of the propulsion device according to one embodiment;

[0021] FIG. 3 is a block diagram of the boat according to one embodiment;

[0022] FIG. 4 is a state transition diagram of a propulsion system according to one embodiment;

[0023] FIG. 5 is a flowchart about setting of a bogen operation mode;

[0024] FIG. 6 is a flowchart showing switching control between a normal operation mode and the bogen operation mode;

[0025] FIG. 7 is a graph illustrating a relationship between a lever opening rate φl and a steering reference angle θsp in the bogen operation mode (bogen control);

[0026] FIG. 8 is a graph illustrating a relationship between a steering instruction value θm and a steering command value θd;

[0027] FIG. 9 is a flowchart showing a method for calculating the steering command value θd;

[0028] FIG. 10 is a graph illustrating a relationship between the steering instruction value θm and the steering command value θd, in a case where the lever opening rate φl is larger than a bogen thrust upper limit value φl_High;

[0029] FIG. 11 is a graph illustrating a relationship between the steering instruction value θm and the steering command value θd, in a case where the lever opening rate φl is equal to or larger than a bogen thrust lower limit value φl_Low and is smaller than an angle switching threshold φlc;

[0030] FIG. 12 is a graph illustrating a relationship between the steering instruction value θm and the steering command value θd, in a case where the lever opening rate φl is equal to or larger than the angle switching threshold φlc and is equal to or smaller than the bogen thrust upper limit value φl_High;

[0031] FIG. 13 is a flowchart about switching control to the normal operation mode from the bogen operation mode;

[0032] FIG. 14 is a timing chart of the boat according to one embodiment;

[0033] FIG. 15 is a diagram showing a relationship between the direction of the propulsion device and the steering command value θd when the boat turns to the right from a forward advancing state, in a case where the steering reference angle θsp of the propulsion device is the maximum;

[0034] FIG. 16 is a diagram showing the relationship between the direction of the propulsion device and the steering command value θd when the boat turns to the right from the forward advancing state, in the case where the steering reference angle θsp of the propulsion device is the maximum;

[0035] FIG. 17 is a diagram showing the relationship between the direction of the propulsion device and the steering command value θd when the boat turns to the right from the forward advancing state, in the case where the steering reference angle θsp of the propulsion device is the maximum;

[0036] FIG. 18 is a diagram showing a relationship between the direction of the propulsion device and the steering command value θd when the boat turns to the left from the forward advancing state, in a case where the steering reference angle θsp of the propulsion device is the maximum;

[0037] FIG. 19 is a diagram showing the relationship between the direction of the propulsion device and the steering command value θd when the boat turns to the left from the forward advancing state, in the case where the steering reference angle θsp of the propulsion device is the maximum;

[0038] FIG. 20 is a diagram showing the operation of the propulsion device when the boat is turning to the left, in a case where the steering reference angle θsp of the propulsion device is smaller than the maximum;

[0039] FIG. 21 is a diagram showing a relationship between the direction of the propulsion device and the steering command value θd when the boat changes to the forward advancing state from the state of turning to the left, in a case where the steering reference angle θsp of the propulsion device is smaller than the maximum; and

[0040] FIG. 22 is a diagram showing the relationship between the direction of the propulsion device and the steering command value θd when the boat changes to the forward advancing state from the state of turning to the left, in the case where the steering reference angle θsp of the propulsion device is smaller than the maximum.DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments in the present disclosure will be described with reference to the drawings. In embodiments and modifications to be described below, corresponding constitutions are denoted by the same reference numbers, and descriptions will be omitted, in some cases. In the following description, for example, expressions indicating relative or absolute arrangements such as “parallel”, “orthogonal”, “center”, and “coaxial” represent not only strictly such arrangements but also a state of being relatively displaced with a tolerance or with an angle or a distance with which the same function is obtainable. In addition, in the present embodiment, “face each other” is not limited to a case where the orthogonal directions (normal directions) of two surfaces coincide with each other, and includes a case where the orthogonal directions intersect each other.

[0042] It is assumed that front, rear, upper, lower, left, and right directions in the following description respectively coincide with the directions of a boat 1. In this case, an arrow FR in the drawing indicates a forward side of the boat 1, an arrow UP in the drawing indicates an upper side of the boat 1, and an arrow LH in the drawing indicates a leftward side of the boat 1. In addition, a center line CL indicates the center position of the boat 1 in a left-right direction (a width direction).Boat 1

[0043] FIG. 1 is a plan view of the boat 1 according to one embodiment.

[0044] The boat 1 illustrated in FIG. 1 includes a hull 2, a plurality of propulsion devices 3, a steering angle inputter 4, a thrust inputter 5, a boat speed sensor 6 (see FIG. 3), an operation unit 7, and a controller 8. Noe that the plurality of propulsion devices 3 and the controller 8 constitute a propulsion system according to the present embodiment.Propulsion Device 3

[0045] The propulsion devices 3 include: a right propulsion device 3a, which is provided on the right side (STBD side) of the stern with respect to the center line CL; and a left propulsion device 3b, which is provided on the left side (PORT side) of the stern with respect to the center line CL. That is, the boat 1 in the present embodiment is a so-called small-sized vessel in which the two propulsion devices 3 (the right propulsion device 3a and the left propulsion device 3b) are provided at both left and right end portions of the stern with the center line CL interposed between them. Hereinafter, in a case where it is not necessary to distinguish between the propulsion devices 3a and 3b, they will be collectively described as the propulsion device 3. Note that the right propulsion device 3a and the left propulsion device 3b are examples of an outer propulsion device and an inner propulsion device.

[0046] FIG. 2 is a side view of the propulsion device 3. FIG. 3 is a block diagram of the boat 1.

[0047] As illustrated in FIGS. 2 and 3, the propulsion device 3 is, for example, an outboard motor. The propulsion device 3 includes: a casing 11; a drive source 12; a drive shaft 13; a propulsor 14; and a shift switching mechanism 15.

[0048] The casing 11 is attached to a bracket 9, which is provided at the stern, via a steering shaft (swivel shaft) 16, which extends in an up-down direction. The propulsion device 3 is attached to the hull 2 so as to be rotatable in a yaw direction around the steering shaft 16 in accordance with the operation on a steering actuator 17 (see FIG. 3).

[0049] The drive source 12 is, for example, an internal combustion engine such as an engine. The drive source 12 is accommodated in an upper portion of the casing 11 with a crankshaft extending in the up-down direction. Dynamic power (engine speed) of the drive source 12 is set, based on an opening degree of a throttle valve. The throttle valve is driven by the operation of a throttle actuator 18 (see FIG. 3).

[0050] The drive shaft 13 transmits the dynamic power generated by the drive source 12 to the propulsor 14 via the shift switching mechanism 15. The drive shaft 13 extends in the up-down direction in the casing 11. An upper end portion of the drive shaft 13 is connected with the drive source 12.

[0051] The propulsor 14 includes a propeller shaft 21 and propellers 22.

[0052] The propeller shaft 21 is provided at a lower end portion of the casing 11 so as to be rotatable around an axis along a front-rear direction. A front end portion of the propeller shaft 21 is connected with the shift switching mechanism 15 in the casing 11.

[0053] The propellers 22 are provided projecting on the outside of the casing 11 at a rear end portion of the propeller shaft 21. The propellers 22 rotate integrally with the propeller shaft 21.

[0054] The shift switching mechanism 15 includes a drive gear 25, a forward gear 26, a reverse gear 27, and a clutch 28.

[0055] The drive gear 25 is provided at a lower end portion of the drive shaft 13. The drive gear 25 is rotatable integrally with the drive shaft 13.

[0056] The forward gear 26 and the reverse gear 27 are rotatably provided at positions that face each other in the front-rear direction interposing the drive gear 25 on the propeller shaft 21. The forward gear 26 and the reverse gear 27 mesh with the drive gear 25. The forward gear 26 and the reverse gear 27 rotate in opposite directions in accordance with the rotation of the drive gear 25.

[0057] The clutch 28 switches a connection state or a disconnection state of the dynamic power between either the forward gear 26 or the reverse gear 27 and the propeller shaft 21. The clutch 28 is provided in a part, positioned between the forward gear 26 and the reverse gear 27, of the propeller shaft 21 so as to be rotatable integrally with the propeller shaft 21. The clutch 28 is provided to be movable in the front-rear direction along the propeller shaft 21 in accordance with the operation of a shift actuator 29. The clutch 28 meshes with the forward gear 26, and is capable of transmitting the rotational force of the forward gear 26 to the propeller shaft 21 (a forward position F). This causes the propellers 22 to rotate in the normal rotation direction, thereby applying thrust in a forward advancing direction to the boat 1. The clutch 28 meshes with the reverse gear 27, and is capable of transmitting the rotational force of the reverse gear 27 to the propeller shaft 21 (a reverse position R). This causes the propellers 22 to rotate in the reverse rotation direction, thereby applying thrust in a rearward advancing direction to the boat 1. On the other hand, in a state in which the clutch 28 does not mesh with either the forward gear 26 or the reverse gear 27, the rotational force is not transmitted to the propeller shaft 21 (a neutral position N).Steering Angle Inputter 4

[0058] As illustrated in FIGS. 1 and 3, the steering angle inputter 4 is provided in a cockpit of the hull 2. The steering angle inputter 4 is, for example, a steering wheel provided to be rotatable clockwise and counterclockwise. The steering angle inputter 4 receives an operation of a user when changing the course of the boat 1 (hull 2). That is, the steering angle inputter 4 receives an operation for changing the direction of dynamic power of the propulsion device 3 around the steering shaft 16. As in the present embodiment, in a case when an outboard motor is used as the propulsion device 3, the direction of the dynamic power of the propulsion device 3 is a steering angle θs. The steering angle θs denotes an inclination angle of the propulsion device 3 around a yaw direction with respect to the center line CL in a plan view. In the present embodiment, the steering angle θs of the propulsion device 3 in a state in which the propeller shaft 21 is parallel to the center line CL in a plan view (a state in which the direction of the dynamic power of each propulsion device 3 is parallel to the front-rear direction of the hull 2) is set as a reference position (0 degrees).

[0059] An operation amount in accordance with the rotation operation on the steering angle inputter 4 is determined by a steering angle sensor 31. The steering angle sensor 31 outputs a determination signal based on an operation amount on the steering angle inputter 4 to the controller 8, as a steering instruction value θm. Note that as the steering angle inputter 4, in addition to the steering wheel, a joystick may be used, and the steering angle inputter 4 may be mounted as a switch or the like of the operation unit 7. In addition to the outboard motor, the propulsion device 3 may be an inboard motor, an inboard and outboard motor, a water jet machine, or the like. For example, in a case of the inboard motor, the direction of the dynamic power of the propulsion device 3 may be changed by changing the direction of a separately provided rudder. For example, in a case of the water jet machine, the direction of the dynamic power of the propulsion device 3 may be changed by changing the direction of a water flow. Further, the outboard motor and a side thruster may be combined together to constitute the propulsion device 3. In this case, the direction of the dynamic power of the propulsion device 3 may be changed by a ratio between the dynamic power of the outboard motor and the dynamic power of the side thruster.Thrust Inputter 5

[0060] The thrust inputter 5 is provided in the cockpit of the hull 2. The thrust inputter 5 is, for example, a throttle lever (accelerator lever). The thrust inputter 5 receives the operation of the user when changing the dynamic power of the propulsion device 3 (requested thrust Sd) or the shift position of the propulsion device 3 (a requested shift position). The thrust inputter 5 is constituted to be capable of reciprocating in accordance with rotation, sliding, or the like. The thrust inputter 5 is capable of reciprocating within an operation area in which three shift areas of the forward position F, the neutral position N, and the reverse position R are aligned.

[0061] In the boat 1, it is possible to set the requested shift position in accordance with the position of the thrust inputter 5 in the operation area. That is, in a case where the thrust inputter 5 is located in the shift area of the forward position F, it is possible to request the controller 8 to set the shift position to the forward position F. In a case where the thrust inputter 5 is located in the shift area of the neutral position N, it is possible to request the controller 8 to set the shift position to the neutral position N. In a case where the thrust inputter 5 is located in the shift area of the reverse position R, it is possible to request the controller 8 to set the shift position to the reverse position R.

[0062] In the boat 1, it is possible to set the requested thrust Sd in accordance with the position of the thrust inputter 5 in the operation area. That is, in a case where the thrust inputter 5 is located in the shift area of the neutral position N, it is possible to request the controller 8 to set the thrust to zero. In a case where the thrust inputter 5 is set in the shift area of the forward position F or the reverse position R, it is possible to request the controller 8 to increase the thrust in the corresponding advancing direction, as the thrust inputter 5 is apart from the shift area of the neutral position N. Note that the position (a lever opening rate φl) of the thrust inputter 5 is determined by a position sensor 32. The position sensor 32 outputs, to the controller 8, a determination signal based on the position (the lever opening rate φl) of the thrust inputter 5.Boat Speed Sensor 6

[0063] As illustrated in FIG. 3, the boat speed sensor 6 determines the speed (boat speed) V of the boat 1. The boat speed sensor 6 receives a positioning signal from a positioning satellite such as a global positioning system (GPS), for example, measures an absolute position (latitude, longitude) of the boat 1, based on the received positioning signal, and calculates the boat speed (the boat speed relative to the ground) V, based on time-series positioning results. The boat speed sensor 6 may be an acoustic sensor or an electromagnetic sensor that determines the boat speed (the boat speed relative to the water) V of the boat 1. The boat speed sensor 6 may estimate the boat speed V, based on the engine speed.Operation Unit 7

[0064] The operation unit 7 receives various operations in the boat 1. The operation unit 7 is constituted to be manually operable by a user, such as a multi-function display (MFD). Note that the operation unit 7 may be an external device such as a mobile terminal connected to the boat 1 in a wired or wireless manner.

[0065] FIG. 4 is a state transition diagram of the propulsion system.

[0066] As illustrated in FIG. 4, in the boat 1 in the present embodiment, for example, while the boat 1 is moving forward, output (a throttle opening degree φt) of the drive source 12 is adjusted in accordance with the position (the lever opening rate φl) of the thrust inputter 5, and thus the dynamic power generated by the propulsion device 3 is adjusted. In addition, in the boat 1 in the present embodiment, for example, a bogen operation mode (Control Bogen) and a normal operation mode (Normal DBW) are switched by the requested thrust Sd (the lever opening rate φl) based on the operation on the thrust inputter 5.

[0067] The normal operation mode is a mode of cruising the boat 1 in a speed region other than a very slow speed region (a normal speed region faster than a very slow speed upper limit threshold Va). The normal operation mode is applied when the lever opening rate φl is larger than, for example, a mode switching threshold φl_e. In the normal operation mode, for example, while the boat 1 is moving forward, the right propulsion device 3a and the left propulsion device 3b are operated in a state in which the steering angles θs of the right propulsion device 3a and the left propulsion device 3b are set to 0 degrees (a non-bogen state). Accordingly, the dynamic power of each of the propulsion devices 3a and 3b acts along the front-rear direction of the hull 2.

[0068] The bogen operation mode is a mode of cruising the boat 1 within a predetermined speed range (for example, approximately 2 km / h to approximately 8 km / h) equal to or smaller than the very slow speed upper limit threshold Va. The bogen operation mode is applied when the lever opening rate φl is equal to or smaller than the mode switching threshold φl_e. The bogen operation mode is a mode of operating the right propulsion device 3a and the left propulsion device 3b while being inclined in opposite directions to each other around the yaw direction with respect to the reference position so that the right propulsion device 3a and the left propulsion device 3b are bilaterally symmetrical with respect to the center line CL. In the bogen operation mode, for example, while the boat 1 is moving forward (the requested shift position is the forward position F), the dynamic power is output from the right propulsion device 3a and the left propulsion device 3b, in a state in which the right propulsion device 3a rotates rightward (counterclockwise) with respect to the reference position, and the left propulsion device 3b rotates leftward (clockwise) with respect to the reference position.

[0069] As illustrated in FIG. 1, in a state in which the right propulsion device 3a and the left propulsion device 3b are steered at an equal steering angle θs as the absolute value and in opposite directions to each other (a bogen state), the dynamic power of each of the propulsion devices 3a and 3b acts while being inclined around the yaw direction with respect to the front-rear direction of the hull 2. In this case, a component force R1 in the left-right direction (force that pushes the hull 2 to the left side) of the dynamic power of the right propulsion device 3a and a component force L1 in the left-right direction (force that pushes the hull 2 to the right side) of the dynamic power of the left propulsion device 3b are offset from each other. For this reason, only component forces R2 and L2 in the front-rear direction of the right propulsion device 3a and the left propulsion device 3b act on the hull 2. The component forces R2 and L2 are smaller by Cosθs than the dynamic power that acts in the front-rear direction in a state in which the steering angles θs of the right propulsion device 3a and the left propulsion device 3b are 0 degrees (the non-bogen state). Therefore, the thrust (resultant force of the component forces R2 and L2) that acts on the hull 2, when the propulsion devices 3a and 3b are in the bogen state, is smaller than the thrust (resultant force of the dynamic power itself) that acts on the hull 2, when the propulsion devices 3a and 3b are in the non-bogen state. Therefore, by conducting the bogen operation mode, it becomes possible to cruise the hull 2 at a very slow speed. Note that as the steering angles θs of the propulsion devices 3a and 3b increase, the component forces R2 and L2 decrease, so that the thrust that acts on the entire hull 2 decreases.Controller 8

[0070] The controller 8 integrally controls the operation of the boat 1 (the propulsion device 3). That is, the controller 8 is an example of a control device. The controller 8 is an integrated or a plurality of electronic control devices included in the boat 1. The controller 8 is implemented by, for example, a hardware processor such as a central processing unit (CPU) executing a program (software) stored in a read only memory (ROM), a random-access memory (RAM), or the like. Some or all of these constituent elements may be implemented by a hardware (a circuit part; including circuitry) such as a large-scale integration (LSI), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a graphics processing unit (GPU), or system on chip (SOC) or may be implemented by software and hardware in cooperation.

[0071] The controller 8 includes a storage 60, an acquisitor 61, a determiner 62, and a drive processor 63.

[0072] The storage 60 includes, for example, a ROM or the like. In the storage 60, programs, various data, and the like necessary for navigating the boat 1 are stored.

[0073] The acquisitor 61 includes, for example, a RAM or the like. The acquisitor 61 acquires determination results of various sensors.

[0074] The determiner 62 includes, for example, a CPU or the like. The determiner 62 determines the state of the boat 1, based on information obtained by the acquisitor 61 and information stored in the storage 60.

[0075] The drive processor 63 includes, for example, a CPU or the like. The drive processor 63 controls the operation of various actuators, based on a determination result in the determiner 62 and the information stored in the storage 60 or the acquisitor 61, and also controls the operation of the engine such as fuel injection or ignition by a known ECU provided in the propulsion device 3.Operation Method of Propulsion System

[0076] Next, an operation method of the propulsion system will be described. Processing to be described below is repeatedly performed, for example, at a predetermined control cycle (for example, several tens of [msec]).

[0077] As illustrated in (1) and (2) of FIG. 4, in the propulsion system in the present embodiment, for example, it is possible to select whether the switching control between the bogen operation mode and the normal operation mode is enabled (a bogen valid state) or disabled (a bogen invalid state) in accordance with the operation (on / off operation) on the operation unit 7.

[0078] FIG. 5 is a flowchart about setting of the bogen operation mode.

[0079] As illustrated in FIGS. 4 and 5, in step S10, the controller 8 determines whether it is in the bogen valid state, based on an operation result on the operation unit 7.

[0080] In a case where a determination result of step S10 is “YES”, the state is determined to be in the bogen valid state, and “1” is set to a standby flag in step S11 ((1) in FIG. 4).

[0081] In a case where the determination result in step S10 is “NO”, the state is determined to be in the bogen invalid state, and “0” is set to the standby flag in step S12 ((2) in FIG. 4). In the bogen invalid state, for example, while the boat 1 is moving forward, the right propulsion device 3a and the left propulsion device 3b are operated in the non-bogen state regardless of the lever opening rate φl.

[0082] FIG. 6 is a flowchart showing switching control between the normal operation mode and the bogen operation mode.

[0083] As illustrated in FIG. 4, in the propulsion system in the present embodiment, the normal operation mode and the bogen operation mode are switched in the bogen valid state.

[0084] As illustrated in FIGS. 4 and 6, in step S20, the controller 8 determines whether a bogen control condition is satisfied. In step S20, it is determined that the bogen control condition is satisfied, in a case where all the following conditions (1-1) to (1-3) are satisfied.

[0085] (1-1) The boat speed V is equal to or lower than the very slow speed upper limit threshold Va.

[0086] (1-2) The shift position is the forward position F.

[0087] (1-3) The lever opening rate φl is equal to or smaller than the mode switching threshold φl_e.

[0088] In a case where none of the conditions (1-1) to (1-3) is satisfied (in a case where the determination result of step S20 is “NO”), processing proceeds to step S21. In step S21, “0” is set to the bogen control flag. In this case, the controller 8 performs the normal operation mode while waiting for the bogen control to be conducted (Standby Bogen).

[0089] On the other hand, in a case where all the conditions (1-1) to (1-3) are satisfied (in a case where the determination result of step S20 is “YES”), the processing proceeds to step S22. In step S22, “1” is set to the bogen control flag ((3) in FIG. 4). In this case, the controller 8 conducts the bogen operation mode (bogen control). Note that in order to suppress the hunting, when the conditions (1-1) to (1-3) continue for a predetermined period of time, “1” may be set to the bogen control flag.

[0090] FIG. 7 is a graph illustrating a relationship between the lever opening rate φl and the steering reference angle θsp in the bogen operation mode (the bogen control). Note that in FIG. 7, in the steering reference angle θsp, a solid line indicates a relationship between the steering reference angle θsp (a right steering reference angle (a first reference angle) θspr) of the right propulsion device 3a and the lever opening rate φl, and a broken line indicates a relationship between the steering reference angle θsp (a left steering reference angle (a second reference angle) θspl) of the left propulsion device 3b and the lever opening rate φl. In addition, in FIG. 7, “R_MAX” indicates the maximum value of the steering angle θs on the right side (+side) with respect to the reference position, and “L_MAX” indicates the maximum value of the steering angle θs on the left side (−side) with respect to the reference position. Hereinafter, the right steering reference angle θspr and the left steering reference angle θspl will be collectively referred to as a steering reference angle θsp, in some cases.

[0091] In the controller 8, a map as illustrated in FIG. 7 is stored beforehand. The steering reference angle θsp is a steering angle θs of each of the propulsion devices 3a and 3b when the hull 2 is, for example, moved forward (straight) at the time of the bogen control. In this case, regarding each steering reference angle θsp, the absolute values of the steering angles θs based on the identical lever opening rate φl are equal to each other so that the directions of the propulsion devices 3a and 3b are bilaterally symmetrical with respect to the center line CL. Specifically, the controller 8 maximizes the steering reference angle θsp of each of the propulsion devices 3a and 3b, in a case where the lever opening rate φl is equal to or larger than a bogen thrust lower limit value φl_Low and is smaller than an angle switching threshold φlc. In the present embodiment, the maximum value of the steering reference angle θsp is equal to the maximum values of the steering angles θs of the propulsion devices 3a and 3b. However, the maximum value of the steering reference angle θsp may be smaller than the maximum values of the steering angles θs of the propulsion devices 3a and 3b.

[0092] In a case where the lever opening rate φl is equal to or larger than the angle switching threshold φlc and is equal to or smaller than a bogen thrust upper limit value φl_High, the controller 8 decreases the steering reference angle θsp of each of the propulsion devices 3a and 3b, as the lever opening rate φl increases. That is, as the steering angles θs of the propulsion devices 3a and 3b decrease, the component forces R2 and L2 increase, and thus the thrust that acts on the entire hull 2 increases. Note that the bogen thrust upper limit value φl_High may be lower than the boat speed V, which is achievable with the minimum output value (the minimum value of the lever opening rate φl) of the drive source 12. In addition, the bogen thrust upper limit value φl_High may be appropriately set by utilizing actual travel data.

[0093] In a case where the lever opening rate φl is larger than the bogen thrust upper limit value φl_High, the controller 8 sets the steering reference angle θsp of each of the propulsion devices 3a and 3b to 0 degrees. That is, in the case where the lever opening rate φl is larger than the bogen thrust upper limit value φl_High, the propulsion devices 3a and 3b are in the non-bogen state, and thus the dynamic power of the propulsion devices 3a and 3b acts along the front-rear direction of the hull 2. Note that the bogen thrust upper limit value φl_High is set to a value smaller than the mode switching threshold φl_e. However, the mode switching threshold φl_e may be set to a value equal to the bogen thrust upper limit value φl_High.

[0094] FIG. 8 is a graph illustrating a relationship between the steering instruction value θm and the steering command value θd. Note that in FIG. 8, a solid line indicates a right steering command value θdr with respect to the steering instruction value θm for the right propulsion device 3a, and a broken line indicates a left steering command value θdl with respect to the steering instruction value θm for the left propulsion device 3b.

[0095] As illustrated in FIG. 8, the controller 8 stores beforehand, for example, a map indicating the relationship between the steering command value θd and the steering instruction value θm at the time of moving forward. By driving the steering actuator 17 so that the steering angle θs corresponds to the steering command value θd, the controller 8 rotates the propulsion device 3 around the yaw direction with respect to the reference position. In the present embodiment, the steering command value θd (the right steering command value θdr) to the right propulsion device 3a and the steering command value θd (the left steering command value θdl) to the left propulsion device 3b at the time of making a turn are set to be different from each other in accordance with the steering angles θs (the steering reference angles θsp) of the propulsion devices 3a and 3b at the time of moving straight (for example, at the time of moving forward). Note that the right steering command value θdr is an example of a first steering command value, an inner command value, or an outer command value, and the left steering command value θdl is an example of a second steering command value, the outer command value, or the inner command value. In addition, hereinafter, the right steering command value θdr and the left steering command value θdl will be collectively referred to as a steering command value θd, in some cases.

[0096] FIG. 9 is a flowchart showing a method for calculating the steering command value θd.

[0097] As illustrated in FIG. 9, in step S30, the controller 8 calculates the steering reference angle θsp, based on the lever opening rate φl. The steering reference angle θsp denotes the steering angles θs of the propulsion devices 3a and 3b, when the steering instruction value θm is 0 degrees. As illustrated in FIG. 7, in the non-bogen state (a state in which the lever opening rate φl is larger than the bogen thrust upper limit value φl_High), the steering reference angle θsp is set to 0 degrees. On the other hand, in the bogen state, the steering reference angle θsp is determined, based on the lever opening rate φl. That is, when the lever opening rate φl is equal to or larger than the bogen thrust lower limit value φl_Low and is smaller than the angle switching threshold φlc, the steering reference angle θsp of each of the propulsion devices 3a and 3b is the maximum (R_MAX, L_MAX). In a case where the lever opening rate φl is equal to or larger than the angle switching threshold φlc and is equal to or smaller than the bogen thrust upper limit value φl_High, the steering reference angle θsp of each of the propulsion devices 3a and 3b decreases, as the lever opening rate φl increases.

[0098] Subsequently, as illustrated in FIG. 9, in step S31, the controller 8 calculates the steering command value θd. The steering command value θd is calculated, based on the steering instruction value θm to be input into the steering angle inputter 4, and denotes the steering angles θs of the propulsion devices 3a and 3b necessary for the boat 1 to make a turn.

[0099] FIG. 10 is a graph illustrating a relationship between the steering instruction value θm and the steering command value θd in a case where the lever opening rate φl is larger than the bogen thrust upper limit value φl_High.

[0100] Specifically, as illustrated in FIGS. 8 and 10, when the propulsion devices 3a and 3b are in the non-bogen state (the steering reference angle θsp=0 degrees), the steering instruction value θm and the steering command value θd are set to be equal to each other for each of the propulsion devices 3a and 3b. That is, for each of the propulsion devices 3a and 3b, the change amount of the steering command value θd relative to the change amount of the steering instruction value θm is equal to each other. However, the change amount of the steering command value θd relative to the change amount of the steering instruction value θm may be different from each other.

[0101] FIGS. 11 and 12 are graphs each illustrating a relationship between the steering instruction value θm and the steering command value θd for every lever opening rate φl. In FIGS. 11 and 12, FIG. 11 illustrates a case where the lever opening rate φl is equal to or larger than the bogen thrust lower limit value φl_Low and is smaller than the angle switching threshold φlc, and FIG. 12 illustrates a case where the lever opening rate φl is equal to or larger than the angle switching threshold φlc and is equal to or smaller than the bogen thrust upper limit value φl_High.

[0102] On the other hand, as illustrated in FIGS. 11 and 12, when the propulsion devices 3a and 3b are in the bogen state (the steering reference angle θsp≠0 degrees), the change amount of the steering command value θd relative to the change amount of the steering instruction value θm is different from each other for each of the propulsion devices 3a and 3b. Specifically, when the boat 1 turns to the right, the change amount of the right steering command value θdr (the inner command value) for the right propulsion device 3a (the inner propulsion device) relative to the change amount of the steering instruction value θm is smaller than the change amount of the left steering command value θdl (the outer command value) for the left propulsion device 3b (the outer propulsion device) relative to the change amount of the steering instruction value θm. In addition, when the boat 1 turns to the right, in the right propulsion device 3a, the change amount of the right steering command value θdr relative to the change amount of the steering instruction value θm decreases, as the right steering reference angle θspr increases. When the boat 1 turns to the right, in a case where the right steering reference angle θspr of the right propulsion device 3a is the maximum (R_MAX), the change amount of the right steering command value θdr relative to the change amount of the steering instruction value θm is zero. That is, when the steering instruction to turn to the right is input in the case where the right steering reference angle θspr of the right propulsion device 3a is the maximum (R_MAX), the state in which the right steering command value θdr is the maximum (R_MAX) is maintained regardless of the steering instruction value θm.

[0103] As illustrated in FIGS. 11 and 12, when the boat 1 turns to the left, the change amount of the left steering command value θdl (the inner command value) for the left propulsion device 3b (the inner propulsion device) relative to the change amount of the steering instruction value θm is smaller than the change amount of the right steering command value θdr (the outer command value) for the right propulsion device 3a (the outer propulsion device) relative to the change amount of the steering instruction value θm. In addition, when the boat 1 turns to the left, in the left propulsion device 3b, the change amount of the left steering command value θdl relative to the change amount of the steering instruction value θm decreases, as the steering reference angle θspl increases. As illustrated in FIG. 11, when the boat 1 turns to the left, in a case where the left steering reference angle θspl of the left propulsion device 3b is the maximum (L_MAX), the change amount of the left steering command value θd relative to the change amount of the steering instruction value θm is zero. That is, when the steering instruction to turn to the left is input, in the case where the left steering reference angle θspl of the left propulsion device 3b is the maximum (L_MAX), the state in which the left steering command value θdl is the maximum (L_MAX) is maintained regardless of the steering instruction value θm.

[0104] FIG. 13 is a flowchart about switching control to the normal operation mode from the bogen operation mode.

[0105] As illustrated in FIG. 13, in step S40, the controller 8 determines whether a bogen cancellation condition is satisfied. In step S40, it is determined that the bogen cancellation condition is satisfied in a case where any one of the following conditions (2-1) to (2-4) is satisfied.

[0106] (2-1) A case where the boat speed V is higher than the very slow speed upper limit threshold Va

[0107] (2-2) A case where the shift position is the forward position F and the lever opening rate φl is larger than the mode switching threshold φl_e

[0108] (2-3) A case where the shift position is the reverse position R.

[0109] (2-4) A case where the ignition is OFF.

[0110] In a case where none of the conditions (2-1) to (2-4) is satisfied (in a case where a determination result of step S40 is “NO”), processing of step S40 is repeated. That is, in a case where the determination result of step S40 is “NO”, the bogen operation mode continues ((4) in FIG. 4).

[0111] On the other hand, in a case where at least one of the conditions (2-1) to (2-4) is satisfied (in a case where the determination result of step S40 is “YES”), the processing proceeds to step S41. In step S41, “1” is set to the bogen cancellation flag. In this case, a cancellation bogen mode is performed ((5) in FIG. 4). The cancellation bogen mode is a mode of returning the steering reference angle θsp (the steering angle θs) of each of the propulsion devices 3a and 3b to 0 degrees. Note that in order to suppress the hunting, when the state of satisfying at least one of the conditions (2-1) to (2-4) continues for a predetermined period of time, the cancellation bogen mode may be performed.

[0112] In step S42, the controller 8 determines whether a bogen escape condition is satisfied. The bogen escape condition is, for example, a case where a difference between the steering angles θs of the propulsion devices 3a and 3b satisfies equal to or smaller than an escape threshold θse.

[0113] In a case where a determination result of step S42 is “NO”, it is determined that the difference between the steering angles θs of the propulsion devices 3a and 3b is still large, and the routine of step S42 is repeated. In this case, the bogen operation mode continues.

[0114] On the other hand, in a case where the determination result of step S42 is “YES”, it is determined that the difference between the steering angles θs of the propulsion devices 3a and 3b has become sufficiently small, and “1” is set to the bogen escape flag. In this case, the controller 8 returns the operation mode to the normal operation mode from the bogen operation mode ((6) in FIG. 4).

[0115] FIG. 14 is a timing chart of the boat 1 according to the present embodiment. FIGS. 15 to 17 are each diagrams showing a relationship between the directions of the propulsion devices 3a and 3b and the steering command value θd when the boat 1 turns to the right from the forward advancing state, in a case where the steering reference angle θsp of each of the propulsion devices 3a and 3b is the maximum. In FIGS. 15 to 17, a circle on a solid line indicates the state of the right propulsion device 3a of the boat 1, which is illustrated on the left side of the graph, and a circle on a broken line indicates the state of the left propulsion device 3b of the boat 1, which is illustrated on the left side of the graph.

[0116] As illustrated in FIG. 14, at time t1, after the ignition is turned on, the bogen operation mode is performed, in a case where the lever opening rate φl is equal to or smaller than the mode switching threshold φl_e, when the shift position is the forward position F. In the present embodiment, since the lever opening rate φl falls within a range between equal to or larger than the bogen thrust lower limit value φl_Low and smaller than the angle switching threshold φlc, the steering reference angle θsp is the maximum as illustrated in FIG. 15.

[0117] As illustrated in FIGS. 14, 16, and 17, the boat 1 is turned to the right from time t2 to time t3 while maintaining the shift position and the lever opening rate φl. Specifically, when the steering instruction value θm necessary for turning to the right is input, the steering command value θd corresponding to the steering reference angle θsp is calculated, based on the steering instruction value θm. In the present embodiment, the steering instruction value θm for turning to the right is input in a state in which the steering reference angle θsp is the maximum, and thus the left propulsion device 3b is steered to the right (counterclockwise) while the steering angle θs of the right propulsion device 3a is maintained. In this manner, the boat 1 turns to the right.

[0118] From time t3 to time t4, the steering instruction value θm is gradually returned to 0 degrees while the shift position and the lever opening rate φl are maintained. Then, each of the propulsion devices 3a and 3b gradually returns to the steering reference angle θsp. In this case, the left propulsion device 3b is steered to the left (clockwise) while the steering angle θs of the right propulsion device 3a is maintained.

[0119] FIGS. 18 and 19 are each diagrams showing a relationship between the directions of the propulsion devices 3a and 3b and the steering command value θd, when the boat 1 turns to the left, in a case where the steering reference angles θsp of the propulsion devices 3a and 3b are the maximum. In FIGS. 18 and 19, a solid circle indicates the state of the right propulsion device 3a of the boat 1, which is illustrated on the left side of the graph, and a broken circle indicates the state of the left propulsion device 3b of the boat 1, which is illustrated on the left side of the graph.

[0120] As illustrated in FIGS. 14, 18, and 19, the boat 1 is turned to the left at time t4 while maintaining the shift position and the lever opening rate φl. Specifically, when the steering instruction value θm necessary for turning to the left is input, the steering command value θd corresponding to the steering reference angle θsp is calculated, based on the steering instruction value θm. In the present embodiment, the steering instruction value θm for turning to the left is input in a state in which the steering reference angle θsp is the maximum, and thus the right propulsion device 3a is steered to the left (clockwise) while maintaining the steering angle θs of the left propulsion device 3b. In this manner, the boat 1 turns to the left.

[0121] FIG. 20 is a diagram showing operation of the propulsion devices 3a and 3b when the lever opening rate φl is increased, in a case where the steering reference angles θsp of the propulsion devices 3a and 3b are smaller than the maximum. In FIG. 20, a circle on a solid line indicates the state of the right propulsion device 3a of the boat 1, which is illustrated on the left side of the graph, and a circle on a broken line indicates the state of the left propulsion device 3b of the boat 1, which is illustrated on the left side of the graph.

[0122] As illustrated in FIGS. 14 and 20, from time t5 to time t6, when the lever opening rate φl is increased, while the steering instruction value θm is maintained, the steering reference angle θsp is changed. Then, when the lever opening rate φl becomes equal to or larger than the angle switching threshold φlc, the steering reference angle θsp is adjusted, based on the lever opening rate φl. However, from time t5 to time t6, the steering instruction value θm is maintained at the maximum, and thus the steering command value θd of each of the propulsion devices 3a and 3b is maintained at L_MAX.

[0123] FIGS. 21 and 22 are each diagrams showing a relationship between the directions of the propulsion devices 3a and 3b and the steering command value θd when the boat 1 changes to the forward advancing state from the state of turning to the left, in a case where the steering reference angles θsp of the propulsion devices 3a and 3b are smaller than the maximum. In FIGS. 21 and 22, a circle on a solid line indicates the state of the right propulsion device 3a of the boat 1, which is illustrated on the left side of the graph, and a circle on a broken line indicates the state of the left propulsion device 3b of the boat 1, which is illustrated on the left side of the graph.

[0124] On the other hand, as illustrated in FIGS. 14, 20, and 21, from time t6 to time t7, when the steering instruction value θm approaches 0 degrees, each of the propulsion devices 3a and 3b is controlled to match the steering reference angle θsp based on the lever opening rate φl.

[0125] Then, as illustrated in FIG. 14, at time t8, when the lever opening rate φl becomes larger than the bogen thrust upper limit value φl_High, the steering angles θs of the propulsion devices 3a and 3b are controlled to be 0 degrees (a state parallel to the center line CL). In this state, the boat 1 cruises while the thrust based on the lever opening rate φl is being applied. Note that when the lever opening rate φl becomes larger than the mode switching threshold φl_e (when the bogen cancellation condition is satisfied), the operation mode returns to the normal operation mode from the bogen operation mode.

[0126] Further, as illustrated in FIGS. 14 and 15, at time t9, when the lever opening rate φl becomes equal to or smaller than the bogen thrust upper limit value φl_High, the operation mode changes to the bogen operation mode again. In this case, the steering angles θs of the propulsion devices 3a and 3b are controlled to be the steering reference angles θsp based on the lever opening rate φl.

[0127] At time t10, when the shift position is switched to the neutral position N from the forward position F, the lever opening rate φl becomes zero, but the bogen state is maintained. In the present embodiment, when the forward position F is switched to the neutral position N, the steering reference angle θsp is controlled to maintain the maximum value. In this case, when returning the operation mode to the forward position F from the neutral position N again, the steering angles θs of the propulsion devices 3a and 3b are adjusted to the steering reference angle θsp based on the lever opening rate φl.

[0128] Then, at time t11, the ignition of the boat 1 is turned off, and thus the steering angles θs of the propulsion devices 3a and 3b return to 0 degrees. Note that in the present embodiment, the case where the steering reference angle θsp is set to 0 degrees when the above-described condition of (2-2) is satisfied at time t8 and the above-described condition of (2-4) is satisfied at time t11 has been described. However, the present disclosure is not limited to this constitution. When the boat speed V is higher than the very slow speed upper limit threshold Va like the above-described condition (2-1), or when the shift position is switched to the reverse position R from the neutral position N like the condition (2-3), the steering reference angle θsp may be set to 0 degrees.

[0129] In this manner, the propulsion system in the present embodiment includes: at least the right propulsion device (the first propulsion device) 3a and the left propulsion device (the second propulsion device) 3b, which are provided side by side in the left-right direction on the hull 2; and the controller 8, which includes at least the processor and the memory and which controls the dynamic power and the direction of the dynamic power of each of the propulsion devices 3a and 3b. When the hull 2 moves forward or rearward, the controller 8 sets the respective directions of the dynamic power of the propulsion devices 3a and 3b to be opposite to each other while being inclined around the yaw direction with respect to the reference position, thereby conducting the bogen control of applying the thrust to the hull 2. The controller 8 calculates the steering reference angle (the first reference angle, the second reference angle) θsp of each of the propulsion devices 3a and 3b based on a thrust instruction value (the lever opening rate φl) given to the hull 2 during the bogen control. Upon receipt of the steering instruction, the controller 8 calculates the steering command value (the first steering command value, the second steering command value) θd based on the steering instruction value θm and the steering reference angle θsp. The controller 8 controls the directions of the dynamic power of the propulsion devices 3a and 3b, based on the steering command value θd.

[0130] According to this constitution, when the steering instruction is input during the bogen control, the directions of the dynamic power of the propulsion devices 3a and 3b (the steering command value θd) are set in accordance with the steering reference angle θsp based on the lever opening rate φl. This enables control of the propulsion devices 3a and 3b with the steering command value θd, which is optimum for the steering reference angle θsp, when the steering instruction is input. As a result, response performance at the time of making a turn can be improved.

[0131] In the propulsion system in the present embodiment, the reference position denotes a position where the direction of the dynamic power of each of the propulsion devices 3a and 3b is parallel to the front-rear direction of the hull 2.

[0132] According to this constitution, for example, when the boat 1 moves forward, the steering reference angle θsp can be calculated using a state in which the dynamic power of the propulsion devices 3a and 3b acts most efficiently as the reference position. Accordingly, it becomes possible to improve the turning performance in a well-balanced manner for the turning performance on both the left and right sides.

[0133] In the propulsion system in the present embodiment, in a case where the lever opening rate φl is equal to or larger than the bogen thrust upper limit value (the thrust threshold) φl_High, the controller 8 sets the steering reference angle θsp to 0 degrees for the hull 2 to move forward or rearward.

[0134] According to this constitution, each of the propulsion devices 3a and 3b is in the non-bogen state, and thus the dynamic power of each of the propulsion devices 3a and 3b acts along the front-rear direction of the hull 2. Thus, the thrust can be efficiently applied to the hull 2.

[0135] In the propulsion system in the present embodiment, in a case where the boat speed V is equal to or higher than the very slow speed upper limit threshold (the boat speed threshold) Va, the controller 8 sets the steering reference angle θsp to 0 degrees for the hull 2 to move forward or rearward.

[0136] According to this constitution, each of the propulsion devices 3a and 3b is in the non-bogen state, and thus the dynamic power of each of the propulsion devices 3a and 3b acts along the front-rear direction of the hull 2. Thus, the thrust can be efficiently applied to the hull 2.

[0137] In the propulsion system in the present embodiment, the controller 8 decreases the steering reference angle θsp, as the lever opening rate φl increases during the bogen control.

[0138] According to this constitution, as the steering reference angles θsp of the propulsion devices 3a and 3b decrease, the component forces R2 and L2 increase, so that the thrust that acts on the entire hull 2 can be increased. Thus, the thrust can be efficiently applied to the hull 2.

[0139] In the propulsion system in the present embodiment, the maximum value of the steering reference angle θsp is equal to the maximum value of the steering angles θs of the propulsion devices 3a and 3b.

[0140] According to this constitution, the component forces R1 and L1 increase, and thus the thrust that acts on the entire hull 2 can be reduced. This enables a reduction of the minimum value of the very slow speed region.

[0141] In the propulsion system in the present embodiment, the controller 8 continues the bogen control, when the shift position is switched to the neutral position N from the forward position F.

[0142] According to this constitution, when the neutral position N is switched to the forward position F again, it is possible to promptly change to the bogen control. This enables improvement in response performance.

[0143] In the propulsion system in the present embodiment, the controller 8 sets the steering reference angle θsp to 0 degrees, when the shift position is switched to the reverse position R from the neutral position N.

[0144] According to this constitution, since the upper limit value of the throttle opening degree φt at the time of moving rearward is generally set to be smaller than the upper limit value of the throttle opening degree φt at the time of moving forward, it becomes possible to simplify the control by setting the non-bogen state at the time of moving rearward.

[0145] In the propulsion system in the present embodiment, out of the propulsion devices 3a and 3b, the outer propulsion device is defined as a propulsion device located on an outer side with respect to the turning direction of the hull 2, the inner propulsion device is defined as a propulsion device located on an inner side with respect to the turning direction of the hull 2. Out of the steering command values θd, the outer command value is defined as a propulsion device located on the outer side with respect to the turning direction of the hull 2, and the inner command value is defined as a propulsion device located on the inner side with respect to the turning direction of the hull 2. During the bogen control, the controller 8 sets the change amount of the outer command value relative to the change amount of the steering instruction value θm to be larger than the change amount of the inner command value relative to the change amount of the steering instruction value θm

[0146] According to this constitution, by increasing the change amount of the outer command value relative to the change amount of the steering instruction value θm for the outer propulsion device that easily affects the turning performance, it becomes possible to improve the response performance at the time of making a turn.

[0147] In the propulsion system in the present embodiment, during the bogen control, as the steering instruction value θm increases on one side of the turning direction, the controller 8 maintains or increases the steering command value θd of the propulsion device located on one side with respect to the steering reference angle θsp, out of the propulsion devices 3a and 3b, and increases the steering command value θd of the propulsion device located on the other side with respect to the steering reference angle θsp.

[0148] According to this constitution, by increasing the absolute value of the steering command value θd relative to the steering reference angle θsp for the outer propulsion device (the propulsion device located on the other side in the turning direction) that easily affects the turning performance, it becomes possible to improve the response performance at the time of making a turn.

[0149] In the propulsion system in the present embodiment, during the bogen control, as the lever opening rate φl increases, the controller 8 decreases the change amount of the outer command value relative to the change amount of the steering instruction value θm.

[0150] According to this constitution, as the lever opening rate φl increases, the steering reference angle θsp decreases, and thus the difference between the steering instruction value θm and the steering command value θd decreases. Therefore, as the lever opening rate φl increases, it is easy to set a desired steering angle θs for the outer propulsion device, even though the change amount of the outer command value relative to the change amount of the steering instruction value θm decreases.

[0151] In the propulsion system in the present embodiment, during the bogen control, as compared with the normal operation mode in which the steering reference angle θsp of each of the propulsion devices 3a and 3b is set to 0 degrees, the controller 8 increases the change amount of the outer command value relative to the change amount of the steering instruction value θm, and decreases the change amount of the inner command value relative to the change amount of the steering instruction value θm.

[0152] According to this constitution, it becomes possible to promptly change to the optimum steering angle θs at the time of making a turn from the steering angles θs of the propulsion devices 3a and 3b during the bogen control. Accordingly, it becomes possible to improve the response performance at the time of making a turn.Other Modifications

[0153] Heretofore, although preferred examples in the present disclosure have been described, the present disclosure is not limited to these examples. Additions, omissions, substitutions, and other changes of the constitution can be made without departing from the gist in the present disclosure. The present disclosure is not limited by the foregoing description, and is limited only by the appended claims.

[0154] In addition, as the type of the hull 2, the present disclosure may be applied to various moving bodies on water such as a V shape hull, a pontoon boat, a center console, a runabout, a fishing boat, and a jet ski.

[0155] In the above-described embodiments, the case where the drive source 12 is an internal combustion engine has been described. However, the present disclosure is not limited to this constitution. The drive source 12 may be an electric motor or the like. In a case of the electric motor, the motor rotation speed, torque, and the like correspond to “thrust”. In this case, the neutral position N is obtained by setting the motor rotation speed to zero.

[0156] When automatic driving or driving assistance (for example, cruise control as autopilot or constant-speed driving) is performed, a computer may be constituted to calculate an instruction value and set a target speed or the like, instead of the user (boat operator) inputting the “requested thrust Sd”.

[0157] In the above-described embodiments, switching between the bogen operation mode and the normal operation mode has been described using the forward movement as an example. However, the present disclosure is not limited to this constitution. It is sufficient if switching between the bogen operation mode and the normal operation mode is performed for at least one of forward movement and rearward movement.

[0158] In the above-described embodiments, the constitution in which the bogen control condition is satisfied in the case where all the conditions (1-1) to (1-3) are satisfied has been described. However, the present disclosure is not limited to this constitution. For example, in a case where at least one of the conditions (1-1) to (1-3) is satisfied, the bogen control condition may be satisfied.

[0159] In the above-described embodiments, the constitution in which the steering reference angle θsp is set to decrease, as the lever opening rate φl increases, during the bogen control has been described. However, the present disclosure is not limited to this constitution. The steering reference angle θsp may be constituted to increase, as the lever opening rate φl increases.

[0160] In the above-described embodiments, the constitution in which the bogen state continues when the shift position is switched to the neutral position N from the forward position F has been described. However, the present disclosure is not limited to this constitution. When the shift position is switched to the neutral position N from the forward position F, it may be constituted to set the non-bogen state.

[0161] In the above-described embodiments, the state has been described in which the direction of the dynamic power of each of the propulsion devices 3 parallel to the front-rear direction of the hull 2 is set as the reference position. However, the present disclosure is not limited to this constitution. The reference position can be changed as appropriate.

[0162] In the above-described embodiments, the constitution has been described in which the steering command value is made different between the outer propulsion device located on the outer side in the turning direction and the inner propulsion device located on the inner side in the turning direction, out of the propulsion devices 3a and 3b. However, the present disclosure is not limited to this constitution. The steering command value may be the same with each other between the outer propulsion device and the inner propulsion device.

[0163] In the above-described embodiments, the constitution of the boat 1 has been described using the case where two propulsion devices 3 are provided as an example. However, the present disclosure is not limited to this constitution. Three or more propulsion devices 3 may be provided. In a case where three or more propulsion devices 3 are provided, it is sufficient if two propulsion devices 3 provided symmetrically with respect to the center line CL constitute at least the first propulsion device and the second propulsion device. For example, in a case where an odd number of the propulsion devices 3 are provided, a pair of propulsion devices provided symmetrically with respect to the center line CL may constitute the first propulsion device and the second propulsion device, and any propulsion device other than the first propulsion device and the second propulsion device may be steered, based on the steering instruction value θm.

[0164] In the above-described embodiments, the constitution has been described in which the valid state and the invalid state of the bogen operation mode are switched in accordance with the operation on the operation unit 7. However, the present disclosure is not limited to this constitution. The bogen operation mode may be always valid.

[0165] In the above-described embodiments, the case where the bogen control is conducted when the shift position is the forward position F has been described. However, the present disclosure is not limited to this constitution. The bogen control may be conducted when the shift position is the reverse position R.

[0166] In the above-described embodiments, the constitution in which the propulsion devices 3 are integrally controlled by the controller 8, which is provided in the hull 2, has been described. However, the present disclosure is not limited to this constitution. The controller 8 may be provided in the propulsion device 3.

[0167] In addition, it is possible to appropriately replace any constituent element in the above-described embodiments with a known constituent element without departing from the gist in the present disclosure, and the above-described modifications may be appropriately combined together.

[0168] A part or the entirety of the propulsion system of the boat according to the above-described embodiments can be additionally described as follows.Supplementary Note 1

[0169] A boat including:

[0170] at least a first propulsion device and a second propulsion device, which are provided side by side in a horizontal direction on a hull; and

[0171] a controller including at least a processor and a memory, the controller being configured to control dynamic power of each the first propulsion device and the second propulsion device and a direction of the dynamic power, in which

[0172] the controller sets directions of the dynamic power of the first propulsion device and the dynamic power of the second propulsion device to be opposite to each other while being inclined around a yaw direction with respect to a reference position, when the hull moves either forward or rearward, and conducts bogen control of applying thrust to the hull, and

[0173] during the bogen control, the controller calculates a first reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the first propulsion device based on a thrust instruction value given to the hull and a second reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the second propulsion device based on the thrust instruction value given to the hull, and

[0174] upon receipt of a steering instruction, the controller calculates a first steering command value based on the steering instruction value and the first reference angle, and also calculates a second steering command value based on the steering instruction value and the second reference angle, and

[0175] the controller controls the direction of the dynamic power of the first propulsion device, based on the first steering command value, and also controls the direction of the dynamic power of the second propulsion device, based on the second steering command value.Supplementary Note 2

[0176] A control device of a boat, the control device including: a controller including at least a processor and a memory, the controller being configured to control dynamic power of each a first propulsion device and a second propulsion device, which are provided side by side in a horizontal direction on a hull, and a direction of the dynamic power, in which

[0177] the controller sets directions of the dynamic power of the first propulsion device and the dynamic power of the second propulsion device to be opposite to each other while being inclined around a yaw direction with respect to a reference position, when the hull moves either forward or rearward, and conducts bogen control of applying thrust to the hull, and

[0178] during the bogen control, the controller calculates a first reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the first propulsion device based on a thrust instruction value given to the hull and a second reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the second propulsion device based on the thrust instruction value given to the hull, and

[0179] upon receipt of a steering instruction, the controller calculates a first steering command value based on the steering instruction value and the first reference angle, and also calculates a second steering command value based on the steering instruction value and the second reference angle, and

[0180] the controller controls the direction of the dynamic power of the first propulsion device, based on the first steering command value, and also controls the direction of the dynamic power of the second propulsion device, based on the second steering command value.

[0181] While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary examples of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.REFERENCE SIGNS LIST1 Boat

[0183] 2 Hull

[0184] 3 Propulsion device

[0185] 3a Right propulsion device (first propulsion device, outer propulsion device, inner propulsion device)

[0186] 3b Left propulsion device (second propulsion device, inner propulsion device, outer propulsion device)

[0187] 4 Steering angle inputter

[0188] 5 Thrust inputter

[0189] 8 Controller

[0190] θd Steering command value

[0191] θdr Right steering command value (first steering command value, outer command value, inner command value)

[0192] θdl Left steering command value (second steering command value, inner command value, outer command value)

[0193] θm Steering instruction value

[0194] θsp Steering reference angle

[0195] θspr Right steering reference angle (first reference angle)

[0196] θspl Left steering reference angle (second reference angle)

[0197] φl Lever opening rate (thrust instruction value)

Claims

1. A propulsion system of a boat, the propulsion system comprising:at least a first propulsion device and a second propulsion device, which are provided side by side in a horizontal direction on a hull; anda controller including at least a processor and a memory, the controller being configured to control dynamic power of each the first propulsion device and the second propulsion device and a direction of the dynamic power, whereinthe controller sets directions of the dynamic power of the first propulsion device and the dynamic power of the second propulsion device to be opposite to each other while being inclined around a yaw direction with respect to a reference position, when the hull moves either forward or rearward, and conducts bogen control of applying thrust to the hull, andduring the bogen control, the controller calculates a first reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the first propulsion device based on a thrust instruction value given to the hull and a second reference angle around the yaw direction with respect to the reference position for the direction of the dynamic power of the second propulsion device based on the thrust instruction value given to the hull, andupon receipt of a steering instruction, the controller calculates a first steering command value based on the steering instruction value and the first reference angle, and also calculates a second steering command value based on the steering instruction value and the second reference angle, andthe controller controls the direction of the dynamic power of the first propulsion device, based on the first steering command value, and also controls the direction of the dynamic power of the second propulsion device, based on the second steering command value.

2. The propulsion system of the boat according to claim 1, wherein the reference position is a position in a state in which the directions of the dynamic power of the first propulsion device and the second propulsion device are parallel to a front-rear direction of the hull.

3. The propulsion system of the boat according to claim 2, wherein in a case where the thrust instruction value is equal to or larger than a thrust threshold, the controller sets each the first reference angle and the second reference angle to 0 degrees for the hull to move either forward or rearward.

4. The propulsion system of the boat according to claim 2, wherein in a case where a boat speed is higher than a boat speed threshold, the controller sets each the first reference angle and the second reference angle to 0 degrees for the hull to move either forward or rearward.

5. The propulsion system of the boat according to claim 1, wherein during the bogen control, the controller decreases the first reference angle and the second reference angle, as the thrust instruction value increases.

6. The propulsion system of the boat according to claim 1, wherein a maximum value of the first reference angle is a maximum angle of the direction of the dynamic power of the first propulsion device, anda maximum value of the second reference angle is a maximum angle of the direction of the dynamic power of the second propulsion device.

7. The propulsion system of the boat according to claim 2, wherein when the shift position is switched to the neutral position from the forward position, the controller continues the bogen control.

8. The propulsion system of the boat according to claim 7, wherein when the shift position is switched to a reverse position from the neutral position, the controller sets each the first reference angle and the second reference angle to 0 degrees.

9. The propulsion system of the boat according to claim 1, whereinout of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, andout of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value,during the bogen control, the controller sets a change amount of the outer command value relative to a change amount of the steering instruction value to be larger than a change amount of the inner command value relative to the change amount of the steering instruction value.

10. The propulsion system of the boat according to claim 1, wherein during the bogen control, as the steering instruction value increases on one side of a turning direction, the controller either maintains or increases a steering command value of a propulsion device located on one side with respect to a steering reference angle, out of the first propulsion device and the second propulsion device, and increases a steering command value of a propulsion device located on the other side with respect to the steering reference angle.

11. The propulsion system of the boat according to claim 4, whereinout of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, andout of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value,during the bogen control, as the thrust instruction value increases, the controller decreases a change amount of the outer command value relative to a change amount of the steering instruction value.

12. The propulsion system of the boat according to claim 1, whereinout of the first propulsion device and the second propulsion device, in a case where a propulsion device located on an outer side with respect to a turning direction of the hull is defined as an outer propulsion device, and a propulsion device located on an inner side with respect to the turning direction of the hull is defined as an inner propulsion device, andout of the first steering command value and the second steering command value, in a case where a command value for the propulsion device located on the outer side with respect to the turning direction of the hull is defined as an outer command value, and a command value for the propulsion device located on the inner side with respect to the turning direction of the hull is defined as an inner command value,during the bogen control, the controller increases a change amount of the outer command value relative to a change amount of the steering instruction value, and decreases a change amount of the inner command value relative to the change amount of the steering instruction value, as compared with a normal operation mode in which the first reference angle and the second reference angle are each set to 0 degrees.

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