System for propelling watercraft, watercraft, and method of propelling watercraft

Abstract

A watercraft propulsion system includes first and second propulsion devices, a joystick, a joystick button, and a main controller. The first and second propulsion devices are attached to a hull of a watercraft. The joystick is configured to operate the first and second propulsion devices. The joystick button is configured to issue a command to transition to a joystick mode to operate the first and second propulsion devices with the joystick. The main controller is configured or programmed to deactivate the joystick mode based on the first and second propulsion devices changing between a stopped state and a started state in the joystick mode.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-201108 filed on Nov. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates to systems for propelling watercraft, watercraft, and methods of propelling watercraft.2. Description of the Related Art

[0003] There is a type of watercraft in which an operating device is operable by a watercraft operator or user, and it has been proposed to use a joystick as the operating device (e.g., see Japan Laid-open Patent Application Publication No. 2023-103075).

[0004] It is possible to operate a propulsion device, installed in or attached to the hull of the watercraft, by operating the joystick. For example, the watercraft is able to move forward by tilting the joystick forward and turn rightward by twisting the joystick rightward.

[0005] However, if the propulsion device is started or stopped while the user is operating the watercraft with the joystick, there is a concern that the watercraft behaves in a manner not intended by the user. If the watercraft is provided with two propulsion devices installed in or attached to a rear portion of the hull thereof, when one of the propulsion devices is stopped, the watercraft is likely to start bow turning even though the joystick is being tilted forward.SUMMARY OF THE INVENTION

[0006] Example embodiments of the present invention provide systems for propelling watercraft, watercraft, and methods of propelling watercraft in which the watercraft are prevented from behaving in a manner not intended by a user of the watercraft.

[0007] A system for propelling a watercraft according to an example embodiment of the present invention includes a propulsion device, a joystick, a mode command input, and a controller. The propulsion device is attached to a hull of the watercraft. The joystick is configured to operate the propulsion device. The mode command input is operable to issue a command to transition to a joystick mode to operate the propulsion device with the joystick. The controller is configured or programed to deactivate the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

[0008] A method of propelling a watercraft according to another example embodiment of the present invention includes transitioning to a joystick mode to operate a propulsion device attached to a hull of the watercraft with a joystick, and deactivating the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

[0009] In the joystick mode of operating the propulsion device with the joystick, the joystick mode is deactivated upon a change in state of the propulsion device to stop the operation with the joystick. Thus, the operation with the joystick is stopped and the watercraft is prevented from behaving in a manner not intended by a user of the watercraft.

[0010] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a plan view of a watercraft including a watercraft propulsion system according to an example embodiment of the present invention.

[0012] FIG. 2 is a side view of the watercraft.

[0013] FIG. 3 is a diagram showing a configuration of a first propulsion device.

[0014] FIG. 4 is a rear view of the first propulsion device as seen from behind the watercraft.

[0015] FIG. 5 is a schematic diagram showing a configuration of a drive unit.

[0016] FIG. 6 is a diagram showing a configuration of the watercraft propulsion system of the watercraft.

[0017] FIG. 7 is a perspective view of a joystick unit.

[0018] FIG. 8 is a diagram showing transitioning between modes.

[0019] FIGS. 9A and 9B are diagrams for explaining a specific example of transitioning from a joystick mode to a normal mode.

[0020] FIGS. 10A and 10B are diagrams for explaining a specific example of transitioning from the joystick mode to the normal mode.

[0021] FIG. 11 is a flowchart showing a series of control actions performed by the watercraft propulsion system according to an example embodiment of the present invention.

[0022] FIG. 12 is a flowchart showing the series of control actions performed by the watercraft propulsion system according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0023] Example embodiments of the present invention will be hereinafter explained with reference to drawings.

[0024] FIG. 1 is a plan view of a watercraft 1 including a watercraft propulsion system (system for propelling a watercraft) 100 according to an example embodiment of the present invention. FIG. 2 is a side view of the watercraft 1 including the watercraft propulsion system 100 according to an example embodiment of the present invention.

[0025] The watercraft 1 includes a hull 2, a first propulsion device 3, and a second propulsion device 4. Each of the first and second propulsion devices 3 and 4 may be, for example, an electric propulsion device including an electric motor as a power source thereof. Each of the first and second propulsion devices 3 and 4 is an outboard motor. The first and second propulsion devices 3 and 4 are attached to a stern 2a of the hull 2. The first and second propulsion devices 3 and 4 are aligned on the stern 2a in the right-and-left direction of the hull 2. The first and second propulsion devices 3 and 4 are disposed line-symmetric to each other with respect to an imaginary center line of the hull 2 that extends perpendicular to the width direction of the hull 2. In the present example embodiment, the first propulsion device 3 is disposed on the left side and the second propulsion device 4 is disposed on the right side. The first and second propulsion devices 3 and 4 have comparable configurations.

[0026] The hull 2 includes an operating seat 5, a joystick 6, and a gauge 7. The operating seat 5 is where a user (or watercraft operator) is seated to operate the hull 2. The joystick 6 is operable by the user to change the route of the watercraft 1 and change the magnitude (output) and the direction (forward or rearward moving direction) of a thrust generated by each of the first and second propulsion devices 3 and 4. The gauge 7 displays a variety of information to operate the watercraft 1.

[0027] FIG. 3 is a diagram showing a configuration of the first propulsion device 3. The first and second propulsion devices 3 and 4 have comparable configurations so the first propulsion device 3 will be exemplified for explaining the configuration of each propulsion device 3, 4. FIG. 4 is a rear view of the first propulsion device 3 as seen from behind the watercraft 1.

[0028] The watercraft 1 includes a bracket 11 to attach the first propulsion device 3 therethrough to the hull 2. The bracket 11 is attached to the stern 2a of the hull 2. The first propulsion device 3 is supported by the bracket 11.

[0029] The first propulsion device 3 includes a base12, an upper housing 13, a lower housing 14, a cover 15, a cowl 16, a drive unit 17, and a steering unit 18. The base 12 is supported by the bracket 11. The upper housing 13 extends downward from the base 12. The lower housing 14 may have the shape of a tube (duct) and is disposed below the upper housing 13. The cover 15 covers the base 12 from below. The cowl 16 covers the base 12 from above.

[0030] The drive unit 17 is disposed inside the lower housing 14. FIG. 5 is a schematic diagram showing a configuration of the drive unit 17. The drive unit 17 includes a propeller 19 and an electric motor 20. The propeller 19 generates the thrust. The electric motor 20 drives the propeller 19. The electric motor 20 includes a rotor 21 and a stator 22.

[0031] The rotor 21 may have the shape of a tube to which the propeller 19 is fixed on the radially inner side thereof. The rotor 21 is rotatably supported by the lower housing 14. The rotor 21 includes a plurality of permanent magnets 23. The permanent magnets 23 are disposed along the circumferential direction of the rotor 21. It should be noted that in FIG. 5, the reference numeral 23 indicates only one of the permanent magnets without indicating the remaining permanent magnets.

[0032] The stator 22 encloses the rotor 21 from radially outside. The stator 22 is fixed to the lower housing 14. The stator 22 includes a plurality of coils 24. The coils 24 are disposed along the circumferential direction of the stator 22. When the coils 24 are electrified, electromagnetic forces are generated such that the rotor 21 is rotated. The propeller 19 is rotated in accordance with the rotation of the rotor 21 such that thrust is generated. It should be noted that in FIG. 5, the reference numeral 24 indicates only one of the coils without indicating the remaining coils.

[0033] As shown in FIG. 3, the steering unit 18 is disposed in a space between the cover 15 and the cowl 16. The steering unit 18 changes right and left the direction of the thrust generated by the drive unit 17. The steering unit 18 includes a steering shaft 25 and a steering motor 26. The steering shaft 25 is joined to upper and lower housings 13 and 14. The steering motor 26 generates a driving force to rotate the steering shaft 25 about the axis thereof. The steering unit 18 may include a reduction gear that reduces the speed of the rotation of the steering motor 26 and transmits the rotation reduced in speed to the steering shaft 25. When the steering motor 26 is driven, the upper and lower housings 13 and 14 are rotated about the steering shaft 25 such that the direction of the thrust generated by the drive unit 17 is able to be changed right and left.

[0034] The watercraft 1 includes a tilt unit 30 and a tilt angle sensor 31. The tilt unit 30 includes a tilt cylinder 32. The tilt cylinder 32 may be a hydraulic cylinder of an electric pump type including an electric pump to cause a hydraulic oil to flow. The tilt cylinder 32 is rotatably joined at one end thereof to a lower support portion 11a of the bracket 11. The tilt cylinder 32 is rotatably joined at the other end thereof to the base 12 through a cylinder coupling bracket 33. The bracket 11 supports a tilt shaft 34 at an upper support portion 11b thereof. The base 12 is joined to the bracket 11 through the tilt shaft 34 and is rotatable about the tilt shaft 34. The tilt shaft 34 extends in the right-and-left direction of the hull 2. The base 12 is rotatable with respect to the bracket 11 in the up-and-down direction. Accordingly, the first propulsion device 3 is movable up and down by rotating about the tilt shaft 34 with respect to the hull 2.

[0035] FIG. 6 is a diagram showing a configuration of the watercraft propulsion system 100 installed in the watercraft 1. The watercraft propulsion system 100 includes the first and second propulsion devices 3 and 4 described above.

[0036] The watercraft propulsion system 100 includes a main controller 101 (an example of a controller), an intra-watercraft network (CAN (Controller Area Network)) 102, a joystick unit 60, a GPS (Global Positioning System) receiver 103, and a compass sensor 104. The main controller 101 is configured or programmed to control the watercraft 1 as a whole. The main controller 101 includes a processor such as a CPU (Central Processing Unit) and memories such as a RAM (Random Access Memory) and a ROM (Read-Only Memory). The main controller 101 stores programs and data to control the watercraft 1 as a whole. The main controller 101 is connected to the intra-watercraft network 102 established in the watercraft 1.

[0037] The joystick unit 60, the GPS receiver 103, the compass sensor 104, the first propulsion device 3, and the second propulsion device 4 are connected to the intra-watercraft network 102.

[0038] The joystick unit 60 includes the joystick 6. The joystick unit 60 generates an operating position signal indicating the operating position of the joystick 6. The joystick unit 60 includes operating buttons 61 to 65 (see FIG. 7 to be described below). The joystick unit 60 generates operating signals of the operating buttons 61 to 65 disposed thereon. The joystick unit 60 will be described in detail in paragraphs below.

[0039] The first propulsion device 3 includes a motor controller 35 and a steering controller 36. The motor controller 35 and the steering controller 36 are connected to the intra-watercraft network 102.

[0040] The motor controller 35 and the steering controller 36 cause the first propulsion device 3 to actuate in response to commands outputted from the main controller 101. The main controller 101 outputs a thrust command and a rudder angle command to the first propulsion device 3. The thrust command includes a shift command (rotational direction command) and an output command. The shift command is a rotational direction command to cause the propeller 19 to stop, rotate in a forward moving rotational direction, or rotate in a rearward moving rotational direction. The output command instructs a magnitude at which the thrust should be generated, i.e., a target value for the thrust (as well as the rotational speed). The rudder angle command instructs a target value for a rudder angle.

[0041] The motor controller 35 controls the electric motor 20 in accordance with the shift command (rotational direction command) and the output command. The motor controller 35 includes a processor such as a CPU and memories such as a RAM and a ROM. The motor controller 35 stores programs and data to control the electric motor 20 in accordance with the shift command and the output command.

[0042] The steering controller 36 controls the steering motor 26 in accordance with the rudder angle command. The steering controller 36 includes a processor such as a CPU and memories such as a RAM and a ROM. The steering controller 36 stores programs and data to control the steering motor 26 in accordance with the rudder angle command.

[0043] The main controller 101 outputs a tilt command to the motor controller 35 through the intra-watercraft network 102. The motor controller 35 causes the tilt cylinder 32 to extend and contract in response to a tilt command signal such that the first propulsion device 3 is caused to tilt up or down.

[0044] The motor controller 35 receives a detection signal inputted thereto from the tilt angle sensor 31. Accordingly, the motor controller 35 obtains information regarding the tilt angle of the first propulsion device 3 and is able to transmit the information regarding the tilt angle to the main controller 101. As with the first propulsion device 3, the second propulsion device 4 also includes the motor controller 35 and the steering controller 36. Additionally, as with the first propulsion device 3, the second propulsion device 4 is also able to change the tilt angle by the tilt cylinder 32. Then, the information regarding the tilt angle is transmitted to the main controller 101 by the tilt angle sensor 31.

[0045] The GPS receiver 103 receives radio waves from artificial satellites circulating about the Earth, specifies the position of the watercraft 1, and outputs not only position data indicating the position of the watercraft 1 but also velocity data indicating the moving speed of the watercraft 1. The position data and the velocity data are obtained by the main controller 101 and are used to displaying or control at least either the position or the compass direction of the watercraft 1.

[0046] The compass sensor 104 detects the compass direction of the watercraft 1 and creates compass direction data. The compass direction data are obtained by the main controller 101.

[0047] The gauge 7 is connected to the main controller 101. The gauge 7 displays a variety of information to operate the watercraft 1. The gauge 7 is connected to the motor controller 35 and the steering controller 36 in the first propulsion device 3 and the motor controller 35 and the steering controller 36 in the second propulsion device 4. The gauge 7 displays a variety of information regarding the operating state of the first propulsion device 3, that of the second propulsion device 4, the position or the compass direction of the watercraft 1, and so forth. The gauge 7 may be provided with an input device 7a such as a touchscreen, one or more buttons, and so forth. When operated by the user, the input device 7a may be configured to output an operating signal to the main controller 101 such that the main controller 101 is able to make various settings or issue various commands.

[0048] The watercraft propulsion system 100 includes a power switch unit 40. The power switch unit 40 is connected to the first and second propulsion devices 3 and 4 to power on or off the first and second propulsion devices 3 and 4. The power switch unit 40 includes a first power switch 41 (an example of a propulsion device command input) and a second power switch 42 (an example of a propulsion device command input). When the first power switch 41 is turned on or turned off, a circuit between the first propulsion device 3 and a battery 110 to supply electric power to the first propulsion device 3 is closed or opened such that the first propulsion device 3 is able to be powered on or powered off. The motor controller 35 in the first propulsion device 3 outputs first propulsion device state information, indicating whether or not the first propulsion device 3 is in a powered-on state, i.e., whether or not the first propulsion device 3 is in a drivable state, to the main controller 101 through the intra-watercraft network 102. When the second power switch 42 is turned on or turned off, a circuit between the second propulsion device 4 and the battery 110 to supply electric power to the second propulsion device 4 is closed or opened such that the second propulsion device 4 is able to be powered on or powered off. The motor controller 35 in the second propulsion device 4 outputs second propulsion device state information, indicating whether or not the second propulsion device 4 is in a powered-on state, i.e., whether or not the second propulsion device 4 is in a drivable state, to the main controller 101 through the intra-watercraft network 102.

[0049] The watercraft propulsion system 100 includes an application switch panel 105. The application switch panel 105 is connected to the intra-watercraft network 102. The application switch panel 105 includes a plurality of function switches 106 to issue commands to execute preliminarily defined functions, respectively. For example, the function switches 106 may include a switch to issue a command to operate the watercraft 1 in an automated manner. More specifically, the function switches 106 may include a switch associated with automated steering to keep the compass direction of the watercraft 1, a switch associated with automated steering to keep the route of the watercraft 1, a switch associated with automated steering to cause the watercraft 1 to sequentially pass through a plurality of specified spots, a switch associated with automated steering to move the watercraft 1 in a predetermined sailing pattern (a zigzag pattern, a spiral pattern, etc.), and so forth. Additionally, the function switches 106 may include one or more switches associated with tilting up or tilting down the first and second propulsion devices 3 and 4.

[0050] FIG. 7 is a perspective view of the joystick unit 60. The joystick unit 60 includes the joystick 6 that is able to not only tilt forward, rearward, rightward, and leftward (i.e., in all the compass directions of 360 degrees) but also turn (twist) about the axis thereof. The joystick unit 60 includes a joystick button 61 (an example of a mode command input), keeping mode setting buttons 62 to 64, and a thrust setting button 65. The joystick button 61 is operable by the user when a joystick mode, which is a control mode (watercraft operating mode) with the joystick 6, is selected by the user.

[0051] The keeping mode setting buttons 62 to 64 are operable by the user to set control modes related to keeping the position or the compass direction (an example of a fixed spot keeping function). Specifically, the keeping mode setting button 62 is operable to set a fixed spot keeping mode (called Stay Point™ mode) to keep both the position of the watercraft 1 and the compass direction of the bow (or the stern) of the watercraft 1. The keeping mode setting button 63 is operable to set a position keeping mode (called Fish Point™ mode) to keep the position of the watercraft 1 without keeping the compass direction of the bow (or the stern) of the watercraft 1. The keeping mode setting button 64 is operable to set a compass direction keeping mode (called Drift Point™ mode) to keep the compass direction of the bow (or the stern) of the watercraft 1 without keeping the position of the watercraft 1.

[0052] When each of the keeping mode setting buttons 62 to 64 is operated by the user, a signal to start a keeping mode associated therewith is outputted to the main controller 101. Then, when each of the keeping mode setting buttons 62 to 64 is operated again by the user, a signal to stop the keeping mode associated therewith is outputted to the main controller 101. For example, when the keeping mode setting button 62 is operated by the user, the fixed spot keeping mode is executed and, then, when the keeping mode setting button 62 is operated again by the user, a signal to stop the fixed spot keeping mode is outputted to the main controller 101.

[0053] The thrust setting button 65 is operable by the user to set the thrust of the first propulsion device 3. The thrust setting button 65 includes a plus button 65a and a minus button 65b. For example, the magnitude of the thrust is set in a plurality of stages. When the plus button 65a is operated, the thrust is increased in magnitude. When the minus button 65b is operated, the thrust is reduced in magnitude. The setting, made by the thrust setting button 65, is outputted as an output signal to the main controller 101.

[0054] The main controller 101 transitions to three modes. FIG. 8 is a diagram showing transitioning among modes of the main controller 101. The main controller 101 transitions to any of a normal mode (M1), the joystick mode (M2), and the keeping mode (M3).

[0055] When the watercraft propulsion system 100 is powered on, the main controller 101 transitions to the normal mode M1. In the normal mode M1, even when the first and second propulsion devices 3 and 4 are in started states by turning on the first and second power switches 41 and 42, the electric motor 20 cannot be driven, and the steering motor 26 keeps the propeller 19 in a neutral position. The neutral position refers to a position in which the propeller 19 is oriented behind the hull 2. In the normal mode M1, even if the joystick 6 is operated by the user, the main controller 101 disables the thrust command and the rudder angle command issued by the operation for the joystick 6. Because of this, even if the joystick 6 is operated by the user in the normal mode M1, the first and second propulsion devices 3 and 4 are not driven.

[0056] In the joystick mode M2, when the joystick 6 is tilted in the back-and-forth direction, the main controller 101 interprets the tilt operation for the joystick 6 as the thrust command (the shift command and the output command). The main controller 101 ignores tilting of the joystick 6 in the right-and-left direction. In other words, when the joystick 6 is tilted, only a back-and-forth directional component of the tilt operation for the joystick 6 is accepted as an effective input and, then, the back-and-forth directional component is interpreted as the thrust command. Specifically, the back-and-forth directional component is interpreted as a forward moving shift command when having a value corresponding to when the joystick 6 is tilted forward and contrarily, the back-and-forth directional component is interpreted as a rearward moving shift command when having a value corresponding to when the joystick 6 is tilted rearward. Then, the magnitude of the back-and-forth directional component is interpreted as a command to instruct the magnitude of the thrust (the output command). The thrust command, interpreted as described above, is outputted from the main controller 101 to the motor controller 35 in the first propulsion device 3 and the motor controller 35 in the second propulsion device 4. On the other hand, in the joystick mode M2, when the joystick 6 is turned (twisted) about the axis thereof, the main controller 101 interprets the twist operation for the joystick 6 as the rudder angle command. In other words, the main controller 101 outputs the rudder angle command, depending on the direction and the amount of twisting the joystick 6 about the axis thereof, to the steering controller 36 in the first propulsion device 3 and the steering controller 36 in the second propulsion device 4.

[0057] The keeping mode M3 includes the fixed spot keeping mode (Stay Point™ mode), the position keeping mode (Fish Point™ mode), and the compass direction keeping mode (Drift Point™ mode), which are set as described above by operating the keeping mode setting buttons 62, 63, and 64, respectively. In the keeping mode M3, the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 are controlled without any manual operation by the watercraft operator. In the keeping mode M3, even if the joystick 6 is operated, the main controller 101 disables both the thrust command and the rudder angle command issued by the operation for the joystick 6.

[0058] For example, in the fixed spot keeping mode (Stay Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on not only the position data and the velocity data, both of which are generated by the GPS receiver 103, but also the compass direction data outputted from the compass sensor 104. Accordingly, the hull 2 is reduced or prevented from fluctuating in position and compass direction.

[0059] On the other hand, in the position keeping mode (Fish Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on the position data and the velocity data, both of which are generated by the GPS receiver 103. Accordingly, the hull 2 is reduced or prevented from fluctuating in position.

[0060] Yet on the other hand, in the compass direction keeping mode (Drift Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on the compass direction data generated by the compass sensor 104. Accordingly, the hull 2 is reduced or prevented from fluctuating in compass direction.

[0061] Next, conditions for transitioning among three modes will be explained. It should be noted that in the following explanation, the “started” state of each propulsion device refers to a state that each propulsion device is in the powered-on state as a result of an operation performed for turning on each power switch associated with each propulsion device. Specifically, the “started” state of each propulsion device is exemplified by a state that the first propulsion device 3 is in the powered-on state as a result of an operation for turning on the first power switch 41. The “started” state of each propulsion device is also exemplified by a state that the second propulsion device 4 is in the powered-on state as a result of an operation performed for turning on the second power switch 42. The “started” state of each propulsion device includes an “undriven” state and a “driven” state. The “undriven” state of each propulsion device refers to a state that each propulsion device is in the powered-on state but is not being driven. Specifically, the state that each propulsion device is not being driven refers to a state that the electric motor 20 and the steering motor 26 are being stopped in each propulsion device. The “driven” state of each propulsion device refers to a state that each propulsion device is in the powered-on state and is being driven. Specifically, the state that each propulsion device is being driven refers to a state that the electric motor 20 and the steering motor 26 are being actuated in each propulsion device. A “stopped” state of each propulsion device refers to a state that each propulsion device is in a powered-off state as a result of an operation performed for turning off each power switch associated with each propulsion device. Specifically, the “stopped” state of each propulsion device is exemplified by a state that the first propulsion device 3 is in the powered-off state as a result of an operation performed for turning off the power switch 41. The “stopped” state of each propulsion device is also exemplified by a state that the second propulsion device 4 is in the powered-off state as a result of an operation performed for turning off the power switch 42.

[0062] When a condition (1) is satisfied, the main controller 101 deactivates the normal mode M1 and transitions to the keeping mode M3. The condition (1) is satisfied when both the first and second propulsion devices 3 and 4 are in the undriven states, and simultaneously, any of the keeping mode setting buttons 62 to 64 is pressed. In the keeping mode M3, an automated operation is executed for the first and second propulsion devices 3 and 4 in accordance with one of the modes of the keeping mode M3, which is associated with the one pressed among the keeping mode setting buttons 62 to 64 in transitioning to the keeping mode M3.

[0063] When a condition (2) or (3) is satisfied, the main controller 101 deactivates the keeping mode M3 and transitions to the normal mode M1. The condition (2) is satisfied when any of the keeping mode setting buttons 62 to 64 is pressed. When any of the keeping mode setting buttons 62 to 64 is pressed by the user in the keeping mode M3, the main controller 101 transitions from the keeping mode M3 to the normal mode M1. The condition (3) is satisfied when either the first or second propulsion device 3, 4 is in the undriven state. Specifically, the condition (3) is satisfied when driving of at least one of the first and second propulsion devices 3 and 4 is stopped due to some reason in the keeping mode M3. It should be noted that the condition (3) may be satisfied when at least one of the first and second power switches 41 and 42 is turned off by the user such that at least one of the first and second propulsion devices 3 and 4 is in the stopped state. Additionally, when the main controller 101 transitions to the normal mode M1, if one of the first and second propulsion devices 3 and 4 is being driven, the main controller 101 outputs stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0064] When a condition (4) is satisfied, the main controller 101 deactivates the keeping mode M3 and transitions to the joystick mode M2. The condition (4) is satisfied when at least one of the first and second propulsion devices 3 and 4 is in the started state, and simultaneously, the joystick button 61 is pressed.

[0065] When a condition (5) is satisfied, the main controller 101 deactivates the joystick mode M2 and transitions to the keeping mode M3. The condition (5) is satisfied when both the first and second propulsion devices 3 and 4 are in the started states, and simultaneously, any of the keeping mode setting buttons 62 to 64 is pressed.

[0066] When a condition (6) is satisfied, the main controller 101 deactivates the normal mode M1 and transitions to the joystick mode M2. The condition (6) is satisfied when at least one of the first and second propulsion devices 3 and 4 is in the started state, and simultaneously, the joystick button 61 is pressed. For example, when both the first and second propulsion devices 3 and 4 are in the powered-on states, if the joystick button 61 is pressed, the main controller 101 transitions from the normal mode M1 to the joystick mode M2. In this case, both the first and second propulsion devices 3 and 4 are driven by operating the joystick 6 in the joystick mode M2. On the other hand, even when the first propulsion device 3 is in the powered-on state but the second propulsion device 4 is in the powered-off state, for instance, if the joystick button 61 is pressed, the main controller 101 transitions from the normal mode M1 to the joystick mode M2 as well. In this case, only the first propulsion device 3 is driven by operating the joystick 6 in the joystick mode M2.

[0067] When a condition (7) or (8) is satisfied, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. The condition (7) is satisfied when the joystick button 61 is pressed. When the joystick button 61 of the joystick unit 60 is pressed by the user in the joystick mode M2, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. At this time, when either the first or second propulsion device 3, 4 is being driven, the main controller 101 outputs stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0068] A condition (8) is satisfied when at least one of the first and second propulsion devices 3 and 4 has been changed between the started state and the stopped state. The condition (8) will be explained below.

[0069] FIGS. 9 and 10 are diagrams for explaining specific examples of transitioning from the joystick mode M2 to the normal mode M1. FIG. 9A shows a state that both the first and second propulsion devices 3 and 4 are being driven in the joystick mode M2. FIG. 9B shows a state obtained when the power switch 41 is operated by the user to power off the first propulsion device 3 in the state shown in FIG. 9A. In FIGS. 9A and 9B, the first propulsion device 3, turned to the stopped state, is illustrated with hatches. By thus powering off the first propulsion device 3, the first propulsion device 3 is changed from the started state to the stopped state. Thus, the condition (8) is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. It should be noted that, when both the first and second propulsion devices 3 and 4 are being driven in the joystick mode M2, if the power switch 42 is operated by the user to power off the second propulsion device 4, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1 as well.

[0070] FIG. 10A shows a state that the first propulsion device 3 is in the started state but the second propulsion device 4 is in the stopped state in the joystick mode M2. In FIGS. 10A and 10B, the second propulsion device 4 in the stopped state is illustrated with hatches. FIG. 10B shows a state obtained when the power switch 42 is operated by the user to power on the second propulsion device 4 in the state shown in FIG. 10A. By thus powering on the second propulsion device 4, the second propulsion device 4 is changed from the stopped state to the started state. Thus, the condition (8) is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. It should be noted that, when the first propulsion device 3 is in the stopped state but the second propulsion device 4 is in the started state in the joystick mode M2, if the power switch 41 is operated by the user to power on the first propulsion device 3, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1 as well.

[0071] Thus, when either the first or second propulsion device 3, 4 has been changed between the started state and the stopped state in the joystick mode M2, the main controller 101 deactivates the joystick mode M2 and then transitions to the normal mode M1 such that it is possible to stop the operation with the joystick 6. Thus, the watercraft 1 can be prevented from behaving in a manner not intended by the user of the watercraft 1. It should be noted that when the main controller 101 transitions to the normal mode M1, if either the first or second propulsion device 3, 4 is being driven, the main controller 101 outputs the stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0072] Next, a series of control actions performed by the watercraft propulsion system 100 according to an example embodiment of the present invention will be explained and, simultaneously, a method of propelling a watercraft will be described as well.

[0073] FIG. 11 is a flowchart showing the series of control actions performed by the watercraft propulsion system 100 according to an example embodiment.

[0074] When a power supply is operated to be powered on in the watercraft propulsion system 100, the main controller 101 transitions to the normal mode M1 in step S1. In the normal mode M1, even if the joystick 6 is operated by the user of the watercraft 1, the first and second propulsion devices 3 and 4 cannot be driven.

[0075] Next, in step S2, the main controller 101 determines whether or not the condition (1) is satisfied. When it is determined that the condition (1) is satisfied in step S2, the main controller 101 deactivates the normal mode M1 and then transitions to the keeping mode M3 in step S3. In the keeping mode M3, one of the modes of the keeping mode M3 is executed that is associated with the one pressed among the keeping mode setting buttons in transitioning to the keeping mode M3. Then, an automated operation is executed for the first and second propulsion devices 3 and 4.

[0076] Next, in step S4, the main controller 101 determines whether or not the condition (2) is satisfied. When it is determined that the condition (2) is satisfied in step S4, the control processing returns to step S1. Then, the main controller 101 deactivates the keeping mode M3, transitions to the normal mode M1, and executes the normal mode M1.

[0077] Contrarily, when it is determined that the condition (2) is not satisfied in step S4, the main controller 101 determines whether or not the condition (3) is satisfied in step S5. When it is determined that the condition (3) is satisfied in step S5, the control process returns to step S1. Then, the main controller 101 deactivates the keeping mode M3, transitions to the normal mode M1, and executes the normal mode M1.

[0078] Contrarily, when the condition (3) is not satisfied in step S5, the main controller 101 determines whether or not the condition (4) is satisfied in step S6. When it is determined that the condition (4) is not satisfied in step S6, the control processing returns to step S3 and, then, the main controller 101 maintains the keeping mode M3.

[0079] Contrarily, when it is determined that the condition (4) is satisfied in step S6, the main controller 101 deactivates the keeping mode M3, transitions to the joystick mode M2, and executes the joystick mode M2 in step S8. In the joystick mode M2, each or either of the first and second propulsion devices 3 and 4 is driven in accordance with an operation of the joystick 6 when in the started state. Specifically, when both of the first and second propulsion devices 3 and 4 are in the started states, both are driven in accordance with the operation of the joystick 6. On the other hand, when only one of the first and second propulsion devices 3 and 4 is in the started state, the one in the started state is driven in accordance with the operation of the joystick 6.

[0080] When the condition (1) is not satisfied in step S2, the control process proceeds to step S7. Then, the main controller 101 determines whether or not the condition (6) is satisfied in step S7. When it is determined that the condition (6) is not satisfied in step S7, the control process returns to step S1 and, then, the main controller 101 maintains the normal mode M1.

[0081] On the other hand, when it is determined that the condition (6) is satisfied in step S7, the main controller 101 deactivates the normal mode M1 and transitions to the joystick mode M2 in step S8.

[0082] Next, the main controller 101 determines whether or not the condition (7) is satisfied in step S9. When it is determined that the condition (7) is satisfied in step S9, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0083] Contrarily, when it is determined that the condition (7) is not satisfied in step S9, the main controller 101 determines whether or not the condition (8) is satisfied in step S10. When it is determined that the condition (8) is satisfied in step S10, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. Contrarily, when it is determined that the condition (8) is not satisfied in step S10, the control process proceeds to step S11.

[0084] Step S10 will be hereinafter described in detail. FIG. 12 is a flowchart showing the determination processes executed in step S10. Step S10 includes step S21 and step S22. As shown in FIG. 12, when it is determined that the condition (7) is not satisfied in step S9, the main controller 101 determines whether or not the first propulsion device 3 has been changed between the started state and the stopped state in step S21. Specifically, the main controller 101 determines whether or not the first propulsion device 3 has been changed from the stopped state to the started state as a result of an operation performed by the user to turn on the power switch 41 when the first propulsion device 3 is in the stopped state, or alternatively, whether or not the first propulsion device 3 has been changed from the started state to the stopped state as a result of an operation performed by the user to turn off the power switch 41 when the first propulsion device 3 is in the started state. The main controller 101 is able to detect the change of the first propulsion device 3 between the started state and the stopped state based on the operating signal outputted from the power switch 41 or the first propulsion device state information.

[0085] When it is determined that the first propulsion device 3 has been changed between the started state and the stopped state in step S21, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2, transitions to the normal mode M1, and disables the operation with the joystick 6.

[0086] When it is determined that the first propulsion device 3 has not been changed between the started state and the stopped state in step S21, the control process proceeds to step S22. The main controller 101 determines whether or not the second propulsion device 4 has been changed between the started state and the stopped state in step S22. Specifically, the main controller 101 determines whether or not the second propulsion device 4 has been changed from the stopped state to the started state as a result of an operation performed by the user to turn on the power switch 42 when the second propulsion device 4 is in the stopped state, or alternatively, whether or not the second propulsion device 4 has been changed from the started state to the stopped state as a result of an operation performed by the user to turn off the power switch 42 when the second propulsion device 4 is in the started state. The main controller 101 is able to detect the change in state of the second propulsion device 4 between the started state and the stopped state based on the operating signal outputted from the power switch 42 or the second propulsion device information.

[0087] In step S22, when it is determined that the second propulsion device 4 has been changed between the started state and the stopped state, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2, transitions to the normal mode M1, and disables the operation with the joystick 6.

[0088] Contrarily, when it is determined that the second propulsion device 4 has not been changed between the started state and the stopped state in step S22, the control process proceeds to step S11.

[0089] As shown in FIG. 11, the main controller 101 determines whether or not the condition (5) is satisfied in step S11. When it is determined that the condition (5) is not satisfied in step S11, the control process returns to step S8 and, then, the main controller 101 maintains the joystick mode M2.

[0090] Contrarily, when it is determined that the condition (5) is satisfied in step S11, the control process proceeds to step S3 and, then, the main controller 101 deactivates the joystick mode M2 and transitions to the keeping mode M3.

[0091] The watercraft 1 and the watercraft propulsion system 100 according to example embodiments of the present invention have the following features.

[0092] The joystick mode M2 is deactivated based on the change of the propulsion device 3 or 4 between the stopped state and the started state in the joystick mode M2. Accordingly, when the propulsion device 3 or 4 has been changed, it is possible to stop the operation with the joystick 6. By thus stopping the operation with the joystick 6, the watercraft 1 can be prevented from behaving in a manner not intended by the user.

[0093] When the propulsion device 3 or 4 has been changed between the stopped state and the started state in accordance with the operation of the power switch 41 or 42 by the user, it is possible to deactivate the joystick mode M2.

[0094] The joystick mode M2 is deactivated when at least one of the first and second propulsion devices 3 and 4 has been changed from the started state to the stopped state in the joystick mode M2. Accordingly, the watercraft 1 can be prevented from behaving in such a manner not intended by the user as follows: one of the first and second propulsion devices 3 and 4 has been changed from the started state to the stopped state such that the watercraft 1 starts performing bow turning even though the joystick 6 is being tilted forward.

[0095] The joystick mode M2 is deactivated when at least one of the first and second propulsion devices 3 and 4 has been changed from the stopped state to the started state in the joystick mode M2. Accordingly, even when one of the first and second propulsion devices 3 and 4 has been changed from the stopped state to the started state, the watercraft 1 can be prevented from behaving in a manner not intended by the user.

[0096] When at least one of the first and second propulsion devices 3 and 4 is operating upon deactivation of the joystick mode M2, the operating propulsion device is stopped. Accordingly, the watercraft 1 can be stopped so as not to behave in a manner not intended by the user.

[0097] The main controller 101 deactivates the joystick mode M2 and thereafter transitions to the normal mode M1 that prevents a manual operation of the watercraft 1 such that the watercraft 1 can be prevented from behaving in a manner not intended by the user even when the joystick 6 is operated.

[0098] The main controller 101 deactivates the joystick mode M2 and thereafter transitions to the joystick mode M2 in response to the command issued thereto from the joystick button 61. Even if the main controller 101 transitions from the joystick mode M2 to the normal mode M1 due to satisfaction of the condition (8), the user herein understands the states of the propulsion devices and the watercraft 1 does not behave in a manner not intended by the user. Thus, the main controller 101 is able to transition to the joystick mode M2 again.

[0099] Example embodiments of the present invention have been explained above. However, the present invention is not limited to the example embodiments described above, and a variety of changes can be made without departing from the gist of the present invention.

[0100] In an example embodiment described above, the watercraft propulsion system 100 includes two propulsion devices 3 and 4. Alternatively, the watercraft propulsion system 100 may include only one propulsion device. In this case, when the only propulsion device has been changed from the started state to the stopped state in accordance with the operation of the power switch by the user in the joystick mode M2, it is determined that the condition (8) described above is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0101] In an example embodiment described above, the watercraft propulsion system 100 includes two propulsion devices 3 and 4. Alternatively, the watercraft propulsion system 100 may include three or more propulsion devices. In this case, when at least one of the plurality of propulsion devices has been changed between the started state and the stopped state in accordance with the operation by the user of the power switch associated with the at least one propulsion device in the joystick mode M2, it is determined that the condition (8) described above is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0102] In an example embodiment described above, each of the first and second propulsion devices 3 and 4 includes the electric motor as the power source thereof. Alternatively, each or either of the first and second propulsion devices 3 and 4 may include the engine as the power source thereof.

[0103] According to example embodiments of the present invention, it is possible to provide systems for propelling watercraft, watercraft, and methods of propelling watercraft such that the watercraft can be prevented from behaving in a manner not intended by a user of the watercraft.

[0104] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0023]Example embodiments of the present invention will be hereinafter explained with reference to drawings.

[0024]FIG. 1 is a plan view of a watercraft 1 including a watercraft propulsion system (system for propelling a watercraft) 100 according to an example embodiment of the present invention. FIG. 2 is a side view of the watercraft 1 including the watercraft propulsion system 100 according to an example embodiment of the present invention.

[0025]The watercraft 1 includes a hull 2, a first propulsion device 3, and a second propulsion device 4. Each of the first and second propulsion devices 3 and 4 may be, for example, an electric propulsion device including an electric motor as a power source thereof. Each of the first and second propulsion devices 3 and 4 is an outboard motor. The first and second propulsion devices 3 and 4 are attached to a stern 2a of the hull 2. The first and second propulsion devices 3 and 4 are aligned on the stern 2a in the right-and-left direction of the h...

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Japanese Patent Application No. 2024-201108 filed on Nov. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The present invention relates to systems for propelling watercraft, watercraft, and methods of propelling watercraft.2. Description of the Related Art

[0003] There is a type of watercraft in which an operating device is operable by a watercraft operator or user, and it has been proposed to use a joystick as the operating device (e.g., see Japan Laid-open Patent Application Publication No. 2023-103075).

[0004] It is possible to operate a propulsion device, installed in or attached to the hull of the watercraft, by operating the joystick. For example, the watercraft is able to move forward by tilting the joystick forward and turn rightward by twisting the joystick rightward.

[0005] However, if the propulsion device is started or stopped while the user is operating the watercraft with the joystick, there is a concern that the watercraft behaves in a manner not intended by the user. If the watercraft is provided with two propulsion devices installed in or attached to a rear portion of the hull thereof, when one of the propulsion devices is stopped, the watercraft is likely to start bow turning even though the joystick is being tilted forward.SUMMARY OF THE INVENTION

[0006] Example embodiments of the present invention provide systems for propelling watercraft, watercraft, and methods of propelling watercraft in which the watercraft are prevented from behaving in a manner not intended by a user of the watercraft.

[0007] A system for propelling a watercraft according to an example embodiment of the present invention includes a propulsion device, a joystick, a mode command input, and a controller. The propulsion device is attached to a hull of the watercraft. The joystick is configured to operate the propulsion device. The mode command input is operable to issue a command to transition to a joystick mode to operate the propulsion device with the joystick. The controller is configured or programed to deactivate the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

[0008] A method of propelling a watercraft according to another example embodiment of the present invention includes transitioning to a joystick mode to operate a propulsion device attached to a hull of the watercraft with a joystick, and deactivating the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

[0009] In the joystick mode of operating the propulsion device with the joystick, the joystick mode is deactivated upon a change in state of the propulsion device to stop the operation with the joystick. Thus, the operation with the joystick is stopped and the watercraft is prevented from behaving in a manner not intended by a user of the watercraft.

[0010] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a plan view of a watercraft including a watercraft propulsion system according to an example embodiment of the present invention.

[0012] FIG. 2 is a side view of the watercraft.

[0013] FIG. 3 is a diagram showing a configuration of a first propulsion device.

[0014] FIG. 4 is a rear view of the first propulsion device as seen from behind the watercraft.

[0015] FIG. 5 is a schematic diagram showing a configuration of a drive unit.

[0016] FIG. 6 is a diagram showing a configuration of the watercraft propulsion system of the watercraft.

[0017] FIG. 7 is a perspective view of a joystick unit.

[0018] FIG. 8 is a diagram showing transitioning between modes.

[0019] FIGS. 9A and 9B are diagrams for explaining a specific example of transitioning from a joystick mode to a normal mode.

[0020] FIGS. 10A and 10B are diagrams for explaining a specific example of transitioning from the joystick mode to the normal mode.

[0021] FIG. 11 is a flowchart showing a series of control actions performed by the watercraft propulsion system according to an example embodiment of the present invention.

[0022] FIG. 12 is a flowchart showing the series of control actions performed by the watercraft propulsion system according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0023] Example embodiments of the present invention will be hereinafter explained with reference to drawings.

[0024] FIG. 1 is a plan view of a watercraft 1 including a watercraft propulsion system (system for propelling a watercraft) 100 according to an example embodiment of the present invention. FIG. 2 is a side view of the watercraft 1 including the watercraft propulsion system 100 according to an example embodiment of the present invention.

[0025] The watercraft 1 includes a hull 2, a first propulsion device 3, and a second propulsion device 4. Each of the first and second propulsion devices 3 and 4 may be, for example, an electric propulsion device including an electric motor as a power source thereof. Each of the first and second propulsion devices 3 and 4 is an outboard motor. The first and second propulsion devices 3 and 4 are attached to a stern 2a of the hull 2. The first and second propulsion devices 3 and 4 are aligned on the stern 2a in the right-and-left direction of the hull 2. The first and second propulsion devices 3 and 4 are disposed line-symmetric to each other with respect to an imaginary center line of the hull 2 that extends perpendicular to the width direction of the hull 2. In the present example embodiment, the first propulsion device 3 is disposed on the left side and the second propulsion device 4 is disposed on the right side. The first and second propulsion devices 3 and 4 have comparable configurations.

[0026] The hull 2 includes an operating seat 5, a joystick 6, and a gauge 7. The operating seat 5 is where a user (or watercraft operator) is seated to operate the hull 2. The joystick 6 is operable by the user to change the route of the watercraft 1 and change the magnitude (output) and the direction (forward or rearward moving direction) of a thrust generated by each of the first and second propulsion devices 3 and 4. The gauge 7 displays a variety of information to operate the watercraft 1.

[0027] FIG. 3 is a diagram showing a configuration of the first propulsion device 3. The first and second propulsion devices 3 and 4 have comparable configurations so the first propulsion device 3 will be exemplified for explaining the configuration of each propulsion device 3, 4. FIG. 4 is a rear view of the first propulsion device 3 as seen from behind the watercraft 1.

[0028] The watercraft 1 includes a bracket 11 to attach the first propulsion device 3 therethrough to the hull 2. The bracket 11 is attached to the stern 2a of the hull 2. The first propulsion device 3 is supported by the bracket 11.

[0029] The first propulsion device 3 includes a base12, an upper housing 13, a lower housing 14, a cover 15, a cowl 16, a drive unit 17, and a steering unit 18. The base 12 is supported by the bracket 11. The upper housing 13 extends downward from the base 12. The lower housing 14 may have the shape of a tube (duct) and is disposed below the upper housing 13. The cover 15 covers the base 12 from below. The cowl 16 covers the base 12 from above.

[0030] The drive unit 17 is disposed inside the lower housing 14. FIG. 5 is a schematic diagram showing a configuration of the drive unit 17. The drive unit 17 includes a propeller 19 and an electric motor 20. The propeller 19 generates the thrust. The electric motor 20 drives the propeller 19. The electric motor 20 includes a rotor 21 and a stator 22.

[0031] The rotor 21 may have the shape of a tube to which the propeller 19 is fixed on the radially inner side thereof. The rotor 21 is rotatably supported by the lower housing 14. The rotor 21 includes a plurality of permanent magnets 23. The permanent magnets 23 are disposed along the circumferential direction of the rotor 21. It should be noted that in FIG. 5, the reference numeral 23 indicates only one of the permanent magnets without indicating the remaining permanent magnets.

[0032] The stator 22 encloses the rotor 21 from radially outside. The stator 22 is fixed to the lower housing 14. The stator 22 includes a plurality of coils 24. The coils 24 are disposed along the circumferential direction of the stator 22. When the coils 24 are electrified, electromagnetic forces are generated such that the rotor 21 is rotated. The propeller 19 is rotated in accordance with the rotation of the rotor 21 such that thrust is generated. It should be noted that in FIG. 5, the reference numeral 24 indicates only one of the coils without indicating the remaining coils.

[0033] As shown in FIG. 3, the steering unit 18 is disposed in a space between the cover 15 and the cowl 16. The steering unit 18 changes right and left the direction of the thrust generated by the drive unit 17. The steering unit 18 includes a steering shaft 25 and a steering motor 26. The steering shaft 25 is joined to upper and lower housings 13 and 14. The steering motor 26 generates a driving force to rotate the steering shaft 25 about the axis thereof. The steering unit 18 may include a reduction gear that reduces the speed of the rotation of the steering motor 26 and transmits the rotation reduced in speed to the steering shaft 25. When the steering motor 26 is driven, the upper and lower housings 13 and 14 are rotated about the steering shaft 25 such that the direction of the thrust generated by the drive unit 17 is able to be changed right and left.

[0034] The watercraft 1 includes a tilt unit 30 and a tilt angle sensor 31. The tilt unit 30 includes a tilt cylinder 32. The tilt cylinder 32 may be a hydraulic cylinder of an electric pump type including an electric pump to cause a hydraulic oil to flow. The tilt cylinder 32 is rotatably joined at one end thereof to a lower support portion 11a of the bracket 11. The tilt cylinder 32 is rotatably joined at the other end thereof to the base 12 through a cylinder coupling bracket 33. The bracket 11 supports a tilt shaft 34 at an upper support portion 11b thereof. The base 12 is joined to the bracket 11 through the tilt shaft 34 and is rotatable about the tilt shaft 34. The tilt shaft 34 extends in the right-and-left direction of the hull 2. The base 12 is rotatable with respect to the bracket 11 in the up-and-down direction. Accordingly, the first propulsion device 3 is movable up and down by rotating about the tilt shaft 34 with respect to the hull 2.

[0035] FIG. 6 is a diagram showing a configuration of the watercraft propulsion system 100 installed in the watercraft 1. The watercraft propulsion system 100 includes the first and second propulsion devices 3 and 4 described above.

[0036] The watercraft propulsion system 100 includes a main controller 101 (an example of a controller), an intra-watercraft network (CAN (Controller Area Network)) 102, a joystick unit 60, a GPS (Global Positioning System) receiver 103, and a compass sensor 104. The main controller 101 is configured or programmed to control the watercraft 1 as a whole. The main controller 101 includes a processor such as a CPU (Central Processing Unit) and memories such as a RAM (Random Access Memory) and a ROM (Read-Only Memory). The main controller 101 stores programs and data to control the watercraft 1 as a whole. The main controller 101 is connected to the intra-watercraft network 102 established in the watercraft 1.

[0037] The joystick unit 60, the GPS receiver 103, the compass sensor 104, the first propulsion device 3, and the second propulsion device 4 are connected to the intra-watercraft network 102.

[0038] The joystick unit 60 includes the joystick 6. The joystick unit 60 generates an operating position signal indicating the operating position of the joystick 6. The joystick unit 60 includes operating buttons 61 to 65 (see FIG. 7 to be described below). The joystick unit 60 generates operating signals of the operating buttons 61 to 65 disposed thereon. The joystick unit 60 will be described in detail in paragraphs below.

[0039] The first propulsion device 3 includes a motor controller 35 and a steering controller 36. The motor controller 35 and the steering controller 36 are connected to the intra-watercraft network 102.

[0040] The motor controller 35 and the steering controller 36 cause the first propulsion device 3 to actuate in response to commands outputted from the main controller 101. The main controller 101 outputs a thrust command and a rudder angle command to the first propulsion device 3. The thrust command includes a shift command (rotational direction command) and an output command. The shift command is a rotational direction command to cause the propeller 19 to stop, rotate in a forward moving rotational direction, or rotate in a rearward moving rotational direction. The output command instructs a magnitude at which the thrust should be generated, i.e., a target value for the thrust (as well as the rotational speed). The rudder angle command instructs a target value for a rudder angle.

[0041] The motor controller 35 controls the electric motor 20 in accordance with the shift command (rotational direction command) and the output command. The motor controller 35 includes a processor such as a CPU and memories such as a RAM and a ROM. The motor controller 35 stores programs and data to control the electric motor 20 in accordance with the shift command and the output command.

[0042] The steering controller 36 controls the steering motor 26 in accordance with the rudder angle command. The steering controller 36 includes a processor such as a CPU and memories such as a RAM and a ROM. The steering controller 36 stores programs and data to control the steering motor 26 in accordance with the rudder angle command.

[0043] The main controller 101 outputs a tilt command to the motor controller 35 through the intra-watercraft network 102. The motor controller 35 causes the tilt cylinder 32 to extend and contract in response to a tilt command signal such that the first propulsion device 3 is caused to tilt up or down.

[0044] The motor controller 35 receives a detection signal inputted thereto from the tilt angle sensor 31. Accordingly, the motor controller 35 obtains information regarding the tilt angle of the first propulsion device 3 and is able to transmit the information regarding the tilt angle to the main controller 101. As with the first propulsion device 3, the second propulsion device 4 also includes the motor controller 35 and the steering controller 36. Additionally, as with the first propulsion device 3, the second propulsion device 4 is also able to change the tilt angle by the tilt cylinder 32. Then, the information regarding the tilt angle is transmitted to the main controller 101 by the tilt angle sensor 31.

[0045] The GPS receiver 103 receives radio waves from artificial satellites circulating about the Earth, specifies the position of the watercraft 1, and outputs not only position data indicating the position of the watercraft 1 but also velocity data indicating the moving speed of the watercraft 1. The position data and the velocity data are obtained by the main controller 101 and are used to displaying or control at least either the position or the compass direction of the watercraft 1.

[0046] The compass sensor 104 detects the compass direction of the watercraft 1 and creates compass direction data. The compass direction data are obtained by the main controller 101.

[0047] The gauge 7 is connected to the main controller 101. The gauge 7 displays a variety of information to operate the watercraft 1. The gauge 7 is connected to the motor controller 35 and the steering controller 36 in the first propulsion device 3 and the motor controller 35 and the steering controller 36 in the second propulsion device 4. The gauge 7 displays a variety of information regarding the operating state of the first propulsion device 3, that of the second propulsion device 4, the position or the compass direction of the watercraft 1, and so forth. The gauge 7 may be provided with an input device 7a such as a touchscreen, one or more buttons, and so forth. When operated by the user, the input device 7a may be configured to output an operating signal to the main controller 101 such that the main controller 101 is able to make various settings or issue various commands.

[0048] The watercraft propulsion system 100 includes a power switch unit 40. The power switch unit 40 is connected to the first and second propulsion devices 3 and 4 to power on or off the first and second propulsion devices 3 and 4. The power switch unit 40 includes a first power switch 41 (an example of a propulsion device command input) and a second power switch 42 (an example of a propulsion device command input). When the first power switch 41 is turned on or turned off, a circuit between the first propulsion device 3 and a battery 110 to supply electric power to the first propulsion device 3 is closed or opened such that the first propulsion device 3 is able to be powered on or powered off. The motor controller 35 in the first propulsion device 3 outputs first propulsion device state information, indicating whether or not the first propulsion device 3 is in a powered-on state, i.e., whether or not the first propulsion device 3 is in a drivable state, to the main controller 101 through the intra-watercraft network 102. When the second power switch 42 is turned on or turned off, a circuit between the second propulsion device 4 and the battery 110 to supply electric power to the second propulsion device 4 is closed or opened such that the second propulsion device 4 is able to be powered on or powered off. The motor controller 35 in the second propulsion device 4 outputs second propulsion device state information, indicating whether or not the second propulsion device 4 is in a powered-on state, i.e., whether or not the second propulsion device 4 is in a drivable state, to the main controller 101 through the intra-watercraft network 102.

[0049] The watercraft propulsion system 100 includes an application switch panel 105. The application switch panel 105 is connected to the intra-watercraft network 102. The application switch panel 105 includes a plurality of function switches 106 to issue commands to execute preliminarily defined functions, respectively. For example, the function switches 106 may include a switch to issue a command to operate the watercraft 1 in an automated manner. More specifically, the function switches 106 may include a switch associated with automated steering to keep the compass direction of the watercraft 1, a switch associated with automated steering to keep the route of the watercraft 1, a switch associated with automated steering to cause the watercraft 1 to sequentially pass through a plurality of specified spots, a switch associated with automated steering to move the watercraft 1 in a predetermined sailing pattern (a zigzag pattern, a spiral pattern, etc.), and so forth. Additionally, the function switches 106 may include one or more switches associated with tilting up or tilting down the first and second propulsion devices 3 and 4.

[0050] FIG. 7 is a perspective view of the joystick unit 60. The joystick unit 60 includes the joystick 6 that is able to not only tilt forward, rearward, rightward, and leftward (i.e., in all the compass directions of 360 degrees) but also turn (twist) about the axis thereof. The joystick unit 60 includes a joystick button 61 (an example of a mode command input), keeping mode setting buttons 62 to 64, and a thrust setting button 65. The joystick button 61 is operable by the user when a joystick mode, which is a control mode (watercraft operating mode) with the joystick 6, is selected by the user.

[0051] The keeping mode setting buttons 62 to 64 are operable by the user to set control modes related to keeping the position or the compass direction (an example of a fixed spot keeping function). Specifically, the keeping mode setting button 62 is operable to set a fixed spot keeping mode (called Stay Point™ mode) to keep both the position of the watercraft 1 and the compass direction of the bow (or the stern) of the watercraft 1. The keeping mode setting button 63 is operable to set a position keeping mode (called Fish Point™ mode) to keep the position of the watercraft 1 without keeping the compass direction of the bow (or the stern) of the watercraft 1. The keeping mode setting button 64 is operable to set a compass direction keeping mode (called Drift Point™ mode) to keep the compass direction of the bow (or the stern) of the watercraft 1 without keeping the position of the watercraft 1.

[0052] When each of the keeping mode setting buttons 62 to 64 is operated by the user, a signal to start a keeping mode associated therewith is outputted to the main controller 101. Then, when each of the keeping mode setting buttons 62 to 64 is operated again by the user, a signal to stop the keeping mode associated therewith is outputted to the main controller 101. For example, when the keeping mode setting button 62 is operated by the user, the fixed spot keeping mode is executed and, then, when the keeping mode setting button 62 is operated again by the user, a signal to stop the fixed spot keeping mode is outputted to the main controller 101.

[0053] The thrust setting button 65 is operable by the user to set the thrust of the first propulsion device 3. The thrust setting button 65 includes a plus button 65a and a minus button 65b. For example, the magnitude of the thrust is set in a plurality of stages. When the plus button 65a is operated, the thrust is increased in magnitude. When the minus button 65b is operated, the thrust is reduced in magnitude. The setting, made by the thrust setting button 65, is outputted as an output signal to the main controller 101.

[0054] The main controller 101 transitions to three modes. FIG. 8 is a diagram showing transitioning among modes of the main controller 101. The main controller 101 transitions to any of a normal mode (M1), the joystick mode (M2), and the keeping mode (M3).

[0055] When the watercraft propulsion system 100 is powered on, the main controller 101 transitions to the normal mode M1. In the normal mode M1, even when the first and second propulsion devices 3 and 4 are in started states by turning on the first and second power switches 41 and 42, the electric motor 20 cannot be driven, and the steering motor 26 keeps the propeller 19 in a neutral position. The neutral position refers to a position in which the propeller 19 is oriented behind the hull 2. In the normal mode M1, even if the joystick 6 is operated by the user, the main controller 101 disables the thrust command and the rudder angle command issued by the operation for the joystick 6. Because of this, even if the joystick 6 is operated by the user in the normal mode M1, the first and second propulsion devices 3 and 4 are not driven.

[0056] In the joystick mode M2, when the joystick 6 is tilted in the back-and-forth direction, the main controller 101 interprets the tilt operation for the joystick 6 as the thrust command (the shift command and the output command). The main controller 101 ignores tilting of the joystick 6 in the right-and-left direction. In other words, when the joystick 6 is tilted, only a back-and-forth directional component of the tilt operation for the joystick 6 is accepted as an effective input and, then, the back-and-forth directional component is interpreted as the thrust command. Specifically, the back-and-forth directional component is interpreted as a forward moving shift command when having a value corresponding to when the joystick 6 is tilted forward and contrarily, the back-and-forth directional component is interpreted as a rearward moving shift command when having a value corresponding to when the joystick 6 is tilted rearward. Then, the magnitude of the back-and-forth directional component is interpreted as a command to instruct the magnitude of the thrust (the output command). The thrust command, interpreted as described above, is outputted from the main controller 101 to the motor controller 35 in the first propulsion device 3 and the motor controller 35 in the second propulsion device 4. On the other hand, in the joystick mode M2, when the joystick 6 is turned (twisted) about the axis thereof, the main controller 101 interprets the twist operation for the joystick 6 as the rudder angle command. In other words, the main controller 101 outputs the rudder angle command, depending on the direction and the amount of twisting the joystick 6 about the axis thereof, to the steering controller 36 in the first propulsion device 3 and the steering controller 36 in the second propulsion device 4.

[0057] The keeping mode M3 includes the fixed spot keeping mode (Stay Point™ mode), the position keeping mode (Fish Point™ mode), and the compass direction keeping mode (Drift Point™ mode), which are set as described above by operating the keeping mode setting buttons 62, 63, and 64, respectively. In the keeping mode M3, the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 are controlled without any manual operation by the watercraft operator. In the keeping mode M3, even if the joystick 6 is operated, the main controller 101 disables both the thrust command and the rudder angle command issued by the operation for the joystick 6.

[0058] For example, in the fixed spot keeping mode (Stay Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on not only the position data and the velocity data, both of which are generated by the GPS receiver 103, but also the compass direction data outputted from the compass sensor 104. Accordingly, the hull 2 is reduced or prevented from fluctuating in position and compass direction.

[0059] On the other hand, in the position keeping mode (Fish Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on the position data and the velocity data, both of which are generated by the GPS receiver 103. Accordingly, the hull 2 is reduced or prevented from fluctuating in position.

[0060] Yet on the other hand, in the compass direction keeping mode (Drift Point™ mode), the main controller 101 controls the output and the rudder angle of the first propulsion device 3 and the output and the rudder angle of the second propulsion device 4 based on the compass direction data generated by the compass sensor 104. Accordingly, the hull 2 is reduced or prevented from fluctuating in compass direction.

[0061] Next, conditions for transitioning among three modes will be explained. It should be noted that in the following explanation, the “started” state of each propulsion device refers to a state that each propulsion device is in the powered-on state as a result of an operation performed for turning on each power switch associated with each propulsion device. Specifically, the “started” state of each propulsion device is exemplified by a state that the first propulsion device 3 is in the powered-on state as a result of an operation for turning on the first power switch 41. The “started” state of each propulsion device is also exemplified by a state that the second propulsion device 4 is in the powered-on state as a result of an operation performed for turning on the second power switch 42. The “started” state of each propulsion device includes an “undriven” state and a “driven” state. The “undriven” state of each propulsion device refers to a state that each propulsion device is in the powered-on state but is not being driven. Specifically, the state that each propulsion device is not being driven refers to a state that the electric motor 20 and the steering motor 26 are being stopped in each propulsion device. The “driven” state of each propulsion device refers to a state that each propulsion device is in the powered-on state and is being driven. Specifically, the state that each propulsion device is being driven refers to a state that the electric motor 20 and the steering motor 26 are being actuated in each propulsion device. A “stopped” state of each propulsion device refers to a state that each propulsion device is in a powered-off state as a result of an operation performed for turning off each power switch associated with each propulsion device. Specifically, the “stopped” state of each propulsion device is exemplified by a state that the first propulsion device 3 is in the powered-off state as a result of an operation performed for turning off the power switch 41. The “stopped” state of each propulsion device is also exemplified by a state that the second propulsion device 4 is in the powered-off state as a result of an operation performed for turning off the power switch 42.

[0062] When a condition (1) is satisfied, the main controller 101 deactivates the normal mode M1 and transitions to the keeping mode M3. The condition (1) is satisfied when both the first and second propulsion devices 3 and 4 are in the undriven states, and simultaneously, any of the keeping mode setting buttons 62 to 64 is pressed. In the keeping mode M3, an automated operation is executed for the first and second propulsion devices 3 and 4 in accordance with one of the modes of the keeping mode M3, which is associated with the one pressed among the keeping mode setting buttons 62 to 64 in transitioning to the keeping mode M3.

[0063] When a condition (2) or (3) is satisfied, the main controller 101 deactivates the keeping mode M3 and transitions to the normal mode M1. The condition (2) is satisfied when any of the keeping mode setting buttons 62 to 64 is pressed. When any of the keeping mode setting buttons 62 to 64 is pressed by the user in the keeping mode M3, the main controller 101 transitions from the keeping mode M3 to the normal mode M1. The condition (3) is satisfied when either the first or second propulsion device 3, 4 is in the undriven state. Specifically, the condition (3) is satisfied when driving of at least one of the first and second propulsion devices 3 and 4 is stopped due to some reason in the keeping mode M3. It should be noted that the condition (3) may be satisfied when at least one of the first and second power switches 41 and 42 is turned off by the user such that at least one of the first and second propulsion devices 3 and 4 is in the stopped state. Additionally, when the main controller 101 transitions to the normal mode M1, if one of the first and second propulsion devices 3 and 4 is being driven, the main controller 101 outputs stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0064] When a condition (4) is satisfied, the main controller 101 deactivates the keeping mode M3 and transitions to the joystick mode M2. The condition (4) is satisfied when at least one of the first and second propulsion devices 3 and 4 is in the started state, and simultaneously, the joystick button 61 is pressed.

[0065] When a condition (5) is satisfied, the main controller 101 deactivates the joystick mode M2 and transitions to the keeping mode M3. The condition (5) is satisfied when both the first and second propulsion devices 3 and 4 are in the started states, and simultaneously, any of the keeping mode setting buttons 62 to 64 is pressed.

[0066] When a condition (6) is satisfied, the main controller 101 deactivates the normal mode M1 and transitions to the joystick mode M2. The condition (6) is satisfied when at least one of the first and second propulsion devices 3 and 4 is in the started state, and simultaneously, the joystick button 61 is pressed. For example, when both the first and second propulsion devices 3 and 4 are in the powered-on states, if the joystick button 61 is pressed, the main controller 101 transitions from the normal mode M1 to the joystick mode M2. In this case, both the first and second propulsion devices 3 and 4 are driven by operating the joystick 6 in the joystick mode M2. On the other hand, even when the first propulsion device 3 is in the powered-on state but the second propulsion device 4 is in the powered-off state, for instance, if the joystick button 61 is pressed, the main controller 101 transitions from the normal mode M1 to the joystick mode M2 as well. In this case, only the first propulsion device 3 is driven by operating the joystick 6 in the joystick mode M2.

[0067] When a condition (7) or (8) is satisfied, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. The condition (7) is satisfied when the joystick button 61 is pressed. When the joystick button 61 of the joystick unit 60 is pressed by the user in the joystick mode M2, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. At this time, when either the first or second propulsion device 3, 4 is being driven, the main controller 101 outputs stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0068] A condition (8) is satisfied when at least one of the first and second propulsion devices 3 and 4 has been changed between the started state and the stopped state. The condition (8) will be explained below.

[0069] FIGS. 9 and 10 are diagrams for explaining specific examples of transitioning from the joystick mode M2 to the normal mode M1. FIG. 9A shows a state that both the first and second propulsion devices 3 and 4 are being driven in the joystick mode M2. FIG. 9B shows a state obtained when the power switch 41 is operated by the user to power off the first propulsion device 3 in the state shown in FIG. 9A. In FIGS. 9A and 9B, the first propulsion device 3, turned to the stopped state, is illustrated with hatches. By thus powering off the first propulsion device 3, the first propulsion device 3 is changed from the started state to the stopped state. Thus, the condition (8) is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. It should be noted that, when both the first and second propulsion devices 3 and 4 are being driven in the joystick mode M2, if the power switch 42 is operated by the user to power off the second propulsion device 4, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1 as well.

[0070] FIG. 10A shows a state that the first propulsion device 3 is in the started state but the second propulsion device 4 is in the stopped state in the joystick mode M2. In FIGS. 10A and 10B, the second propulsion device 4 in the stopped state is illustrated with hatches. FIG. 10B shows a state obtained when the power switch 42 is operated by the user to power on the second propulsion device 4 in the state shown in FIG. 10A. By thus powering on the second propulsion device 4, the second propulsion device 4 is changed from the stopped state to the started state. Thus, the condition (8) is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. It should be noted that, when the first propulsion device 3 is in the stopped state but the second propulsion device 4 is in the started state in the joystick mode M2, if the power switch 41 is operated by the user to power on the first propulsion device 3, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1 as well.

[0071] Thus, when either the first or second propulsion device 3, 4 has been changed between the started state and the stopped state in the joystick mode M2, the main controller 101 deactivates the joystick mode M2 and then transitions to the normal mode M1 such that it is possible to stop the operation with the joystick 6. Thus, the watercraft 1 can be prevented from behaving in a manner not intended by the user of the watercraft 1. It should be noted that when the main controller 101 transitions to the normal mode M1, if either the first or second propulsion device 3, 4 is being driven, the main controller 101 outputs the stop commands to both the motor controller 35 and the steering controller 36 in the driven one of the first and second propulsion devices 3 and 4. When receiving the stop command, the motor controller 35 stops the electric motor 20. On the other hand, when receiving the stop command, the steering controller 36 drives the steering motor 26 to move the propeller 19 to the neutral position and thereafter stops the steering motor 26.

[0072] Next, a series of control actions performed by the watercraft propulsion system 100 according to an example embodiment of the present invention will be explained and, simultaneously, a method of propelling a watercraft will be described as well.

[0073] FIG. 11 is a flowchart showing the series of control actions performed by the watercraft propulsion system 100 according to an example embodiment.

[0074] When a power supply is operated to be powered on in the watercraft propulsion system 100, the main controller 101 transitions to the normal mode M1 in step S1. In the normal mode M1, even if the joystick 6 is operated by the user of the watercraft 1, the first and second propulsion devices 3 and 4 cannot be driven.

[0075] Next, in step S2, the main controller 101 determines whether or not the condition (1) is satisfied. When it is determined that the condition (1) is satisfied in step S2, the main controller 101 deactivates the normal mode M1 and then transitions to the keeping mode M3 in step S3. In the keeping mode M3, one of the modes of the keeping mode M3 is executed that is associated with the one pressed among the keeping mode setting buttons in transitioning to the keeping mode M3. Then, an automated operation is executed for the first and second propulsion devices 3 and 4.

[0076] Next, in step S4, the main controller 101 determines whether or not the condition (2) is satisfied. When it is determined that the condition (2) is satisfied in step S4, the control processing returns to step S1. Then, the main controller 101 deactivates the keeping mode M3, transitions to the normal mode M1, and executes the normal mode M1.

[0077] Contrarily, when it is determined that the condition (2) is not satisfied in step S4, the main controller 101 determines whether or not the condition (3) is satisfied in step S5. When it is determined that the condition (3) is satisfied in step S5, the control process returns to step S1. Then, the main controller 101 deactivates the keeping mode M3, transitions to the normal mode M1, and executes the normal mode M1.

[0078] Contrarily, when the condition (3) is not satisfied in step S5, the main controller 101 determines whether or not the condition (4) is satisfied in step S6. When it is determined that the condition (4) is not satisfied in step S6, the control processing returns to step S3 and, then, the main controller 101 maintains the keeping mode M3.

[0079] Contrarily, when it is determined that the condition (4) is satisfied in step S6, the main controller 101 deactivates the keeping mode M3, transitions to the joystick mode M2, and executes the joystick mode M2 in step S8. In the joystick mode M2, each or either of the first and second propulsion devices 3 and 4 is driven in accordance with an operation of the joystick 6 when in the started state. Specifically, when both of the first and second propulsion devices 3 and 4 are in the started states, both are driven in accordance with the operation of the joystick 6. On the other hand, when only one of the first and second propulsion devices 3 and 4 is in the started state, the one in the started state is driven in accordance with the operation of the joystick 6.

[0080] When the condition (1) is not satisfied in step S2, the control process proceeds to step S7. Then, the main controller 101 determines whether or not the condition (6) is satisfied in step S7. When it is determined that the condition (6) is not satisfied in step S7, the control process returns to step S1 and, then, the main controller 101 maintains the normal mode M1.

[0081] On the other hand, when it is determined that the condition (6) is satisfied in step S7, the main controller 101 deactivates the normal mode M1 and transitions to the joystick mode M2 in step S8.

[0082] Next, the main controller 101 determines whether or not the condition (7) is satisfied in step S9. When it is determined that the condition (7) is satisfied in step S9, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0083] Contrarily, when it is determined that the condition (7) is not satisfied in step S9, the main controller 101 determines whether or not the condition (8) is satisfied in step S10. When it is determined that the condition (8) is satisfied in step S10, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1. Contrarily, when it is determined that the condition (8) is not satisfied in step S10, the control process proceeds to step S11.

[0084] Step S10 will be hereinafter described in detail. FIG. 12 is a flowchart showing the determination processes executed in step S10. Step S10 includes step S21 and step S22. As shown in FIG. 12, when it is determined that the condition (7) is not satisfied in step S9, the main controller 101 determines whether or not the first propulsion device 3 has been changed between the started state and the stopped state in step S21. Specifically, the main controller 101 determines whether or not the first propulsion device 3 has been changed from the stopped state to the started state as a result of an operation performed by the user to turn on the power switch 41 when the first propulsion device 3 is in the stopped state, or alternatively, whether or not the first propulsion device 3 has been changed from the started state to the stopped state as a result of an operation performed by the user to turn off the power switch 41 when the first propulsion device 3 is in the started state. The main controller 101 is able to detect the change of the first propulsion device 3 between the started state and the stopped state based on the operating signal outputted from the power switch 41 or the first propulsion device state information.

[0085] When it is determined that the first propulsion device 3 has been changed between the started state and the stopped state in step S21, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2, transitions to the normal mode M1, and disables the operation with the joystick 6.

[0086] When it is determined that the first propulsion device 3 has not been changed between the started state and the stopped state in step S21, the control process proceeds to step S22. The main controller 101 determines whether or not the second propulsion device 4 has been changed between the started state and the stopped state in step S22. Specifically, the main controller 101 determines whether or not the second propulsion device 4 has been changed from the stopped state to the started state as a result of an operation performed by the user to turn on the power switch 42 when the second propulsion device 4 is in the stopped state, or alternatively, whether or not the second propulsion device 4 has been changed from the started state to the stopped state as a result of an operation performed by the user to turn off the power switch 42 when the second propulsion device 4 is in the started state. The main controller 101 is able to detect the change in state of the second propulsion device 4 between the started state and the stopped state based on the operating signal outputted from the power switch 42 or the second propulsion device information.

[0087] In step S22, when it is determined that the second propulsion device 4 has been changed between the started state and the stopped state, the control process returns to step S1. Then, the main controller 101 deactivates the joystick mode M2, transitions to the normal mode M1, and disables the operation with the joystick 6.

[0088] Contrarily, when it is determined that the second propulsion device 4 has not been changed between the started state and the stopped state in step S22, the control process proceeds to step S11.

[0089] As shown in FIG. 11, the main controller 101 determines whether or not the condition (5) is satisfied in step S11. When it is determined that the condition (5) is not satisfied in step S11, the control process returns to step S8 and, then, the main controller 101 maintains the joystick mode M2.

[0090] Contrarily, when it is determined that the condition (5) is satisfied in step S11, the control process proceeds to step S3 and, then, the main controller 101 deactivates the joystick mode M2 and transitions to the keeping mode M3.

[0091] The watercraft 1 and the watercraft propulsion system 100 according to example embodiments of the present invention have the following features.

[0092] The joystick mode M2 is deactivated based on the change of the propulsion device 3 or 4 between the stopped state and the started state in the joystick mode M2. Accordingly, when the propulsion device 3 or 4 has been changed, it is possible to stop the operation with the joystick 6. By thus stopping the operation with the joystick 6, the watercraft 1 can be prevented from behaving in a manner not intended by the user.

[0093] When the propulsion device 3 or 4 has been changed between the stopped state and the started state in accordance with the operation of the power switch 41 or 42 by the user, it is possible to deactivate the joystick mode M2.

[0094] The joystick mode M2 is deactivated when at least one of the first and second propulsion devices 3 and 4 has been changed from the started state to the stopped state in the joystick mode M2. Accordingly, the watercraft 1 can be prevented from behaving in such a manner not intended by the user as follows: one of the first and second propulsion devices 3 and 4 has been changed from the started state to the stopped state such that the watercraft 1 starts performing bow turning even though the joystick 6 is being tilted forward.

[0095] The joystick mode M2 is deactivated when at least one of the first and second propulsion devices 3 and 4 has been changed from the stopped state to the started state in the joystick mode M2. Accordingly, even when one of the first and second propulsion devices 3 and 4 has been changed from the stopped state to the started state, the watercraft 1 can be prevented from behaving in a manner not intended by the user.

[0096] When at least one of the first and second propulsion devices 3 and 4 is operating upon deactivation of the joystick mode M2, the operating propulsion device is stopped. Accordingly, the watercraft 1 can be stopped so as not to behave in a manner not intended by the user.

[0097] The main controller 101 deactivates the joystick mode M2 and thereafter transitions to the normal mode M1 that prevents a manual operation of the watercraft 1 such that the watercraft 1 can be prevented from behaving in a manner not intended by the user even when the joystick 6 is operated.

[0098] The main controller 101 deactivates the joystick mode M2 and thereafter transitions to the joystick mode M2 in response to the command issued thereto from the joystick button 61. Even if the main controller 101 transitions from the joystick mode M2 to the normal mode M1 due to satisfaction of the condition (8), the user herein understands the states of the propulsion devices and the watercraft 1 does not behave in a manner not intended by the user. Thus, the main controller 101 is able to transition to the joystick mode M2 again.

[0099] Example embodiments of the present invention have been explained above. However, the present invention is not limited to the example embodiments described above, and a variety of changes can be made without departing from the gist of the present invention.

[0100] In an example embodiment described above, the watercraft propulsion system 100 includes two propulsion devices 3 and 4. Alternatively, the watercraft propulsion system 100 may include only one propulsion device. In this case, when the only propulsion device has been changed from the started state to the stopped state in accordance with the operation of the power switch by the user in the joystick mode M2, it is determined that the condition (8) described above is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0101] In an example embodiment described above, the watercraft propulsion system 100 includes two propulsion devices 3 and 4. Alternatively, the watercraft propulsion system 100 may include three or more propulsion devices. In this case, when at least one of the plurality of propulsion devices has been changed between the started state and the stopped state in accordance with the operation by the user of the power switch associated with the at least one propulsion device in the joystick mode M2, it is determined that the condition (8) described above is satisfied such that the main controller 101 deactivates the joystick mode M2 and transitions to the normal mode M1.

[0102] In an example embodiment described above, each of the first and second propulsion devices 3 and 4 includes the electric motor as the power source thereof. Alternatively, each or either of the first and second propulsion devices 3 and 4 may include the engine as the power source thereof.

[0103] According to example embodiments of the present invention, it is possible to provide systems for propelling watercraft, watercraft, and methods of propelling watercraft such that the watercraft can be prevented from behaving in a manner not intended by a user of the watercraft.

[0104] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0023]Example embodiments of the present invention will be hereinafter explained with reference to drawings.

[0024]FIG. 1 is a plan view of a watercraft 1 including a watercraft propulsion system (system for propelling a watercraft) 100 according to an example embodiment of the present invention. FIG. 2 is a side view of the watercraft 1 including the watercraft propulsion system 100 according to an example embodiment of the present invention.

[0025]The watercraft 1 includes a hull 2, a first propulsion device 3, and a second propulsion device 4. Each of the first and second propulsion devices 3 and 4 may be, for example, an electric propulsion device including an electric motor as a power source thereof. Each of the first and second propulsion devices 3 and 4 is an outboard motor. The first and second propulsion devices 3 and 4 are attached to a stern 2a of the hull 2. The first and second propulsion devices 3 and 4 are aligned on the stern 2a in the right-and-left direction of the h...

Claims

1. A system for propelling a watercraft, the system comprising:a propulsion device attached to a hull of the watercraft;a joystick configured to operate the propulsion device;a mode command input operable to issue a command to transition to a joystick mode to operate the propulsion device with the joystick; anda controller configured or programed to deactivate the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

2. The system according to claim 1, further comprising:a propulsion device command input operable to issue a command to change the propulsion device between the stopped state and the started state.

3. The system according to claim 1, wherein the controller is configured or programed to deactivate the joystick mode when the propulsion device has been changed from the started state to the stopped state in the joystick mode.

4. The system according to claim 1, whereina plurality of propulsion devices including the propulsion device are attached to the hull; andthe controller is configured or programed to deactivate the joystick mode when at least one of the plurality of propulsion devices has been changed from the started state to the stopped state in the joystick mode.

5. The system according to claim 1, whereina plurality of propulsion devices including the propulsion device are attached to the hull; andthe controller is configured or programed to deactivate the joystick mode when at least one of the plurality of propulsion devices has been changed from the stopped state to the started state in the joystick mode.

6. The system according to claim 4, wherein, when at least one of the plurality of propulsion devices is operating upon deactivation of the joystick mode, the controller is configured or programed to cause the at least one of the plurality of propulsion devices to stop operating.

7. The system according to claim 1, wherein the controller is configured or programed to deactivate the joystick mode and thereafter transition to a mode preventing manual operation of the watercraft.

8. The system according to claim 1, wherein the controller is configured or programed to deactivate the joystick mode and thereafter transition to the joystick mode in response to a command issued thereto from the mode command input.

9. The system according to claim 1, wherein the propulsion device includes an electric motor as a power source thereof.

10. A watercraft comprising:a hull; andthe system according to claim 1 on the hull.

11. A method of propelling a watercraft, the method comprising:transitioning to a joystick mode to operate a propulsion device with a joystick, the propulsion device being attached to a hull of the watercraft; anddeactivating the joystick mode based on the propulsion device changing between a stopped state and a started state in the joystick mode.

12. The system according to claim 5, wherein, when at least one of the plurality of propulsion devices is operating upon deactivating the joystick mode, the controller is configured or programed to cause the at least one of the plurality of propulsion devices to stop operating.

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