SYSTEM FOR CONTROLLING WATERCRAFT, METHOD OF CONTROLLING WATERCRAFT, AND WATERCRAFT

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2024-201119 filed on Nov. 18, 2024. The entire contents of this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to systems for controlling watercraft, methods of controlling watercraft, and watercraft.

2. Description of the Related Art

Japan Laid-open Patent Application Publication No. H02-227396 discloses a system for operating a watercraft with a joystick. The system disclosed in Japan Laid-open Patent Application Publication No. H02-227396 includes a plurality of marine propulsion devices, a joystick, and a controller. The joystick is operable to tilt in a back-and-forth direction and in a sideways direction. The controller controls the marine propulsion devices to generate thrusts in accordance with the tilting of the joystick. The controller controls the rudder angles and the outputs of the marine propulsion devices in accordance with the tilt direction and the tilt amount of the joystick.

When the watercraft is moved in a sideways direction by tilting the joystick in a sideways direction, the rudder angles of the marine propulsion devices are controlled such that a resultant force of the thrusts generated by the marine propulsion devices is oriented in the sideways direction. Because of this, the maximum thrusts oriented in the sideways direction from the marine propulsion devices are smaller in magnitude than those oriented in the forward or rearward direction from the marine propulsion devices.

For example, suppose the following situation: the watercraft is being moved in a sideways direction by tilting the joystick; then, the joystick is tilted in the forward or rearward direction. In this situation, when the thrusts oriented in the forward or rearward direction become excessively greater in magnitude than those oriented in the sideways direction, there is a concern about a deterioration in the comfort level of the watercraft. Because of this, for instance, the thrusts generated by the marine propulsion devices when the joystick is tilted in the back-and-forth direction are limited in magnitude compared to those generated by the marine propulsion devices when the joystick is tilted in the sideways direction. In other words, when the watercraft is operated with the joystick, the maximum thrusts oriented in the back-and-forth direction are inevitably limited in magnitude. Thus, there is still room for improvement in the operability of the watercraft with the joystick.

SUMMARY OF THE INVENTION

Example embodiments of the present invention enhance the operability of watercraft with joysticks.

A system according to an example embodiment of the present invention relates to a system for controlling a watercraft and includes a plurality of marine propulsion devices, a joystick, a thrust selector, and a controller. The joystick is operable to tilt in a back-and-forth direction and in a sideways direction intersecting with the back-and-forth direction. The thrust selector is operable to select one of a plurality of thrust modes including a limiting mode and a non-limiting mode. The limiting mode limits a forward thrust and a rearward thrust, whereas the non-limiting mode does not limit at least one of the forward thrust and the rearward thrust. The forward thrust is generated by each of the plurality of marine propulsion devices when the joystick is tilted forward, whereas the rearward thrust is generated by each of the plurality of marine propulsion devices when the joystick is tilted rearward. The controller is configured or programed to control a rudder angle and an output of each of the plurality of marine propulsion devices in accordance with the selected one of the plurality of thrust modes, a tilt direction of the joystick, and a tilt amount of the joystick.

A method according to another example embodiment of the present invention relates to a method for controlling a watercraft including a plurality of marine propulsion devices and a joystick operable to tilt in a back-and-forth direction and in a sideways direction intersecting with the back-and-forth direction. The method includes controlling a rudder angle and an output of each of the plurality of marine propulsion devices in accordance with a selected one of a plurality of thrust modes, a tilt direction of the joystick, and a tilt amount of the joystick. The plurality of thrust modes include a limiting mode and a non-limiting mode. The limiting mode limits a forward thrust and a rearward thrust, whereas the non-limiting mode does not limit at least one of the forward thrust and the rearward thrust. The forward thrust is generated by each of the plurality of marine propulsion devices when the joystick is tilted forward, whereas the rearward thrust is generated by each of the plurality of marine propulsion devices when the joystick is tilted rearward.

In the systems and methods according to example embodiments of the present invention, when the non-limiting mode is selected by the thrust selector, the controller does not limit at least one of the forward thrust and the rearward thrust. Put differently, in the non-limiting mode, the controller is able to increase at least one of the forward thrust and the rearward thrust in magnitude to a thrust corresponding to the maximum output of each of the plurality of marine propulsion device. Accordingly, when the forward thrust is not limited in the non-limiting mode, trailering to load the watercraft on a trailer, for instance, is enabled by operating the watercraft with the joystick. On the other hand, when the rearward thrust is not limited in the non-limiting mode, great deceleration of the watercraft, for instance, is enabled by operating the watercraft with the joystick. As a result, it is possible to enhance the operability of the watercraft with the joystick.

According to example embodiments of the present invention, it is possible to enhance the operability of watercraft with joysticks.

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

FIG. 1 is a perspective view of a watercraft to which marine propulsion devices are mounted according to an example embodiment of the present invention.

FIG. 2 is a side view of one of the marine propulsion devices.

FIG. 3 is a diagram for explaining an electric motor.

FIG. 4 is a schematic diagram showing a configuration of a watercraft operating system.

FIG. 5 is a front view of a joystick.

FIG. 6 is a flowchart showing a series of processes to be executed by a watercraft operating controller.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the present invention will be hereinafter explained with reference to drawings. FIG. 1 is a perspective view of a watercraft 10 including a watercraft operating system 100 according to the present example embodiment. The watercraft 10 includes a plurality of marine propulsion devices 1a and 1b. In the present example embodiment, the marine propulsion devices 1a and 1b are electric outboard motors as an example. The marine propulsion devices 1a and 1b are attached to the stern of a hull 10a of the watercraft 10. The marine propulsion devices 1a and 1b are aligned in the right-and-left direction of the watercraft 10. Each marine propulsion device 1a, 1b generates a thrust to propel the watercraft 10.

FIG. 2 is a side view of the marine propulsion device 1a. The structure of the marine propulsion device 1a will be hereinafter explained, however, the structure of the marine propulsion device 1a is the same as the marine propulsion device 1b. The marine propulsion device 1a is attached to the hull 10a through a bracket 11. The marine propulsion device 1a is supported by the bracket 11.

The marine propulsion device 1a includes an upper portion 12, a lower portion 13, a propeller 14, a steering device 15, and an electric motor 16 (see FIG. 3). The upper portion 12 is attached to the bracket 11. The lower portion 13 is disposed below the bracket 11. The lower portion 13 is pivotable about the axis of a steering axle 15a (to be described below) with respect to the upper portion 12. The lower portion 13 includes a case portion 13a and a duct 13b. The case portion 13a is integral with the duct 13b. The duct 13b is disposed below the case portion 13a. The duct 13b has a tubular shape. The propeller 14 is disposed on the duct 13b of the lower portion 13. The propeller 14 generates the thrust when rotated by the driving force of the electric motor 16.

The steering device 15 is configured to pivot the lower portion 13. By pivoting the lower portion 13, the steering device 15 changes the orientation of the thrust generated by the rotation of the propeller 14. The steering device 15 includes the steering axle 15a. The steering axle 15a extends in the up-and-down direction. The steering axle 15a is connected to the upper portion 12 and the duct 13b of the lower portion 13. The steering device 15 includes a motor (not shown in the drawings) to rotate the steering axle 15a about the axis thereof.

The electric motor 16 is driven when supplied with electric power from a battery (not shown in the drawings) disposed in the hull 10a. The electric motor 16 includes a stator portion 16a and a rotor portion 16b. The stator portion 16a is fixed to the duct 13b. The stator portion 16a includes a coil (not shown in the drawings). The rotor portion 16b is fixed to the propeller 14. The stator portion 16a is disposed opposite to the rotor portion 16b. The rotor portion 16b includes a plurality of magnets (not shown in the drawings). When the coil of the stator portion 16a is electrified, the propeller 14 is rotated together with the rotor portion 16b.

FIG. 4 is a schematic diagram showing a configuration of the watercraft operating system 100. The marine propulsion device 1a includes a motor controller 17 and a steering controller 18. The motor controller 17 and the steering controller 18 include control circuits, each of which 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 motor controller 17 has stored programs and data to control the electric motor 16. The motor controller 17 controls the rotational direction and the output of the electric motor 16 in accordance with a command signal outputted thereto from a watercraft operating controller 30 (to be described below).

The steering controller 18 controls the driving of the steering device 15 in accordance with a command signal outputted thereto from the watercraft operating controller 30. The steering controller 18 has stored programs and data to control the steering device 15.

The marine propulsion device 1b is comparable in configuration to the marine propulsion device 1a. Thus, the marine propulsion device 1b includes a steering device 19, an electric motor 20, a motor controller 21, and a steering controller 22.

The watercraft operating system 100 includes a steering wheel 24, a remote controller 25, a joystick 26, and a thrust selector 27. The steering wheel 24, the remote controller 25, the joystick 26, and the thrust selector 27 are disposed in a cockpit 10b of the watercraft 10. The steering wheel 24, the remote controller 25, the joystick 26, and the thrust selector 27 are manually operable.

The steering wheel 24 enables a vessel operator to manipulate the turning direction of the watercraft 10. The steering wheel 24 includes a sensor 24a. The sensor 24a outputs a steering signal indicating the operating direction and the operating amount of the steering wheel 24.

The remote controller 25 includes a throttle lever 25a. The throttle lever 25a enables the vessel operator to regulate the magnitude of the thrust generated by each marine propulsion device 1a, 1b. The throttle lever 25a also enables the vessel operator to switch the direction of the thrust generated by each marine propulsion device 1a, 1b between a forward moving direction and a rearward moving direction. The throttle lever 25a is operable from a neutral position to a forward moving position and a rearward moving position. The neutral position is an intermediate position between the forward moving position and the rearward moving position. The throttle lever 25a includes a sensor 25b. The sensor 25b outputs a throttle signal indicating the operating direction and the operating amount of the throttle lever 25a.

The joystick 26 is tiltable from the neutral position in the back-and-forth direction and the right-and-left direction (sideways direction). In other words, the joystick 26 is tiltable in all compass directions. The joystick 26 is rotatable about a rotational axis Ax1. In other words, the joystick 26 is operable to twist clockwise and counterclockwise about the rotational axis Ax1. The joystick 26 includes a sensor 26a. The sensor 26a outputs an operating signal according to the operation of the joystick 26. The operating signal contains information regarding the tilt direction and the tilt amount of the joystick 26. The operating signal also contains information regarding the twist direction and the twist amount of the joystick 26. The rudder angle, the magnitude of the output, and the direction of the output of each marine propulsion device 1a, 1b are controlled in accordance with the tilt amount and the tilt direction of the joystick 26.

FIG. 5 is a front view of the joystick 26. The joystick 26 includes a joystick button 26b. The joystick button 26b switches between the following modes: a joystick mode to operate the watercraft 10 using the joystick 26 and a normal mode to operate the watercraft 10 using the remote controller 25 and the steering wheel 24.

The thrust selector 27 is disposed in the vicinity of, e.g., adjacent to, the joystick 26. The thrust selector 27 is used in the joystick mode. The thrust selector 27 is operable to select one of a plurality of thrust modes. The thrust modes are used in the joystick mode.

The thrust modes include a limiting mode and a non-limiting mode. The limiting mode is a mode in which a forward moving thrust and a rearward moving thrust are limited in magnitude. The forward moving thrust is generated by each marine propulsion device 1a, 1b when the joystick 26 it tilted forward, whereas the rearward moving thrust is generated by each marine propulsion device 1a, 1b when the joystick 26 is tilted rearward. The non-limiting mode is as a mode in which at least one of the forward moving thrust and the rearward moving thrust is not limited in magnitude. In the present example embodiment, the non-limiting mode is a mode in which both the forward moving thrust and the rearward moving thrust are not limited in magnitude. Each of the forward moving thrust and the rearward moving thrust is a thrust oriented along the back-and-forth direction of the watercraft 10. In other words, each of the forward moving thrust and the rearward moving thrust is a thrust to be generated in a condition that the rudder angle of each marine propulsion device 1a, 1b is 0 degrees.

In the non-limiting mode, when the joystick 26 is operated forward or rearward to a fully tilted position, the output (e.g., rotational speed) of each electric motor 16, 20 is controlled to be the maximum. The maximum output of each electric motor 16, 20 is synonymous with the output produced from each marine propulsion device 1a, 1b when the throttle lever 25a is tilted forward or rearward to the fully tilted position. On the other hand, in the limiting mode, when the joystick 26 is operated forward or rearward to the fully tilted position, the output of each electric motor 16, 20 is limited to being smaller in magnitude than the maximum output thereof.

The plurality of thrust modes have different thrust levels from each other. The non-limiting mode has a higher thrust level than a thrust level of the limiting mode. The non-limiting mode has the highest thrust level among the plurality of thrust modes. The magnitude of the output of each marine propulsion device 1a, 1b, depending on the tilt amount of the joystick 26, increases with the increase in thrust levels. The upper limit of the thrust generated by each marine propulsion device 1a, 1b increases with the increase in thrust levels.

The thrust selector 27 is operable to select one of the plurality of thrust levels as the thrust level to operate the watercraft 100 with the joystick 26. For example, the thrust selector 27 is able to select one of five-stage thrust levels, composed of levels 1 to 5, as the thrust level to operate the watercraft 100 with the joystick 26.

The thrust selector 27 includes a plus switch 27a and a minus switch 27b. When the plus switch 27a is pressed once, the thrust level at the present stage is increased by one stage. When the minus switch 27b is pressed once, the thrust level at the present stage is reduced by one stage. The thrust selector 27 outputs a setting signal indicating the thrust level selected in accordance with such an operation by the vessel operator as described herein. It should be noted that the thrust selector 27 is not limited to switches, and alternatively, may be a touchscreen or the like.

In the present example embodiment, amongst the plurality of thrust levels, the level 4 and lower correspond to the limiting mode, whereas the level 5 corresponds to the non-limiting mode. Put differently, in the present example embodiment, switching between the limiting mode and the non-limiting mode is executed by changing between the thrust levels. Specifically, when changing between the thrust levels from the level 4 to the level 5 by operating the plus switch 27a of the thrust selector 27, switching between the thrust modes is made from the limiting mode to the non-limiting mode. Contrarily, when changing between the thrust levels from the level 5 to the level 4 by operating the minus switch 27b of the thrust selector 27, switching between the thrust modes is made from the non-limiting mode to the limiting mode.

The watercraft operating system 100 includes the watercraft operating controller 30. The watercraft operating controller 30 includes a processor such as a CPU and memories such as a RAM and a ROM. The watercraft operating controller 30 has stored programs and data to control the marine propulsion devices 1a and 1b. The watercraft operating controller 30 is connected not only to the motor controller 17 and the steering controller 18 but also to the motor controller 21 and the steering controller 22 through wired or wireless communication. The watercraft operating controller 30 is connected to the steering wheel 24, the remote controller 25, the joystick 26, and the thrust selector 27 through wired or wireless communication.

The watercraft operating controller 30 outputs command signals not only to the motor controller 17 and the steering controller 18 but also to the motor controller 21 and the steering controller 22 based on signals outputted thereto from the sensors 24a and 25b. The watercraft operating controller 30 controls the rudder angle, the magnitude of the output, and the direction of the output of each marine propulsion device 1a, 1b through each motor controller 17, 21 and each steering controller 18, 22.

The watercraft operating controller 30 receives an operating signal outputted thereto from the thrust selector 27. The watercraft operating controller 30 controls the rudder angle, the magnitude of the output, and the direction of the output of each marine propulsion device 1a, 1b in accordance with the selected thrust mode, the tilt direction of the joystick 26, and the tilt amount of the joystick 26. In the present example embodiment, the watercraft operating controller 30 controls the rudder angle, the magnitude of the output, and the direction of the output of each marine propulsion device 1a, 1b in accordance with the selected thrust level, the thrust mode associated with the selected thrust level, the tilt direction of the joystick 26, and the tilt amount of the joystick 26.

The watercraft operating controller 30 controls each marine propulsion device 1a, 1b to generate a thrust in a direction corresponding to the tilt direction of the joystick 26 with a magnitude depending on the tilt amount of the joystick 26 as long as it does not exceed the upper limit of thrust of the selected thrust level. The watercraft operating controller 30 increases the output of each marine propulsion device 1a, 1b, the magnitude of which depends on the tilt amount of the joystick 26, with each increase in the thrust level.

The watercraft operating controller 30 changes the rudder angle of each marine propulsion device 1a, 1b such that the watercraft 10 performs bow turning in a direction corresponding to the twist direction of the joystick 26. The watercraft operating controller 30 causes each marine propulsion device 1a, 1b to generate a thrust in accordance with the twist amount of the joystick 26.

The watercraft operating controller 30 changes the rudder angle of each marine propulsion device 1a, 1b such that the watercraft 10 turns when the joystick 26 is tilted forward or rearward and twisted. At this time, the watercraft operating controller 30 causes each marine propulsion device 1a, 1b to generate a thrust in accordance with the tilt amount of the joystick 26 and changes the rudder angle of each marine propulsion device 1a, 1b such that the watercraft 10 turns in a direction corresponding to the twist direction of the joystick 26.

In the non-limiting mode, when the joystick 26 is tilted only forward or rearward, the watercraft operating controller 30 does not limit the forward thrust or the rearward thrust to be generated by each marine propulsion device 1a, 1b. Put differently, in the non-limiting mode, when the joystick 26 is operated forward or rearward to the fully tilted position, the watercraft operating controller 30 controls the output (e.g., rotational speed) of each electric motor 16, 20 to be the maximum. In the non-limiting mode, when the joystick 26 is operated forward and either rightward or leftward, or alternatively, when the joystick 26 is operated rearward and either rightward or leftward, the watercraft operating controller 30 limits the maximum output of each marine propulsion device 1a, 1b. In other words, when the watercraft 10 is moved in a sideways direction, the maximum output of each marine propulsion device 1a, 1b is limited in magnitude. For example, in the non-limiting mode, when the rudder angle of each marine propulsion device 1a, 1b is 0 degrees, the forward thrust and the rearward thrust are able to be increased in magnitude to a thrust corresponding to the maximum output of each marine propulsion device 1a, 1b.

In the limiting mode, when the joystick 26 is operated forward or rearward to the fully tilted position, the watercraft operating controller 30 limits the forward thrust or the rearward thrust to be generated by each marine propulsion device 1a, 1b. In the limiting mode, the watercraft operating controller 30 limits the maximum of the forward thrust generated when the joystick 26 is tilted forward to be less than or equal to the maximum of the thrust oriented in the sideways direction from each marine propulsion device 1a, 1b in accordance with the selected thrust level. As to the present example embodiment, in the limiting mode, the watercraft operating controller 30 limits the magnitude of the forward thrust generated when the joystick 26 is operated forward to the fully tilted position to be equal to the maximum of the thrust oriented in the sideways direction from each marine propulsion device 1a, 1b in accordance with the selected thrust level.

In the non-limiting mode, the watercraft operating controller 30 limits the maximum output of each marine propulsion device 1a, 1b when the joystick 26 is tilted and twisted. In the non-limiting mode, when the joystick 26 is released from being twisted, the watercraft operating controller 30 releases the maximum output of each marine propulsion device 1a, 1b from being limited.

FIG. 6 is a flowchart showing a series of thrust mode selecting processes to be executed by the watercraft operating controller 30. In step S1, the watercraft operating controller 30 receives an operating signal from the thrust selector 27. The watercraft operating controller 30 sets one of the thrust levels as a selected thrust level in accordance with the operating signal outputted thereto from the thrust selector 27. In step S2, the watercraft operating controller 30 determines whether or not the thrust level set in step S1 is the highest among the thrust levels. In more detail, as to the present example embodiment, in step S2, the watercraft operating controller 30 determines whether or not the thrust level set in step S1 is the level 5.

In step S2, when the watercraft operating controller 30 determines that the thrust level set in S1 is the highest among the thrust levels, the process proceeds to step S3, then, the watercraft operating controller 30 sets the non-limiting mode as a selected thrust mode. Contrarily, in step S2, when the watercraft operating controller 30 determines that the thrust level set in step S1 is not the highest among the thrust levels (i.e., any of the levels 1 to 4), the process proceeds to step S4, then, the watercraft operating controller 30 sets the limiting mode as the selected thrust mode. The watercraft operating controller 30 maintains the thrust mode until receiving a new operating signal from the thrust selector 27. When receiving a new operating signal from the thrust selector 27, the watercraft operating controller 30 executes the new thrust mode.

In the watercraft operating system 100 according to an example embodiment explained above, when the non-limiting mode is selected by the thrust selector 27 in the joystick mode, the watercraft operating controller 30 does not limit the forward thrust and the rearward thrust. In more detail, when the thrust level set by the thrust selector 27 is the highest among the thrust levels, the watercraft operating controller 30 does not limit the forward thrust and the rearward thrust. Accordingly, in the non-limiting mode, the watercraft operating controller 30 is able to increase the forward thrust and the rearward thrust in magnitude to a thrust corresponding to the maximum output of each marine propulsion device 1a, 1b in accordance with the operation of the joystick 26. As a result, trailering to load the watercraft 10 on a trailer, for instance, is enabled by operating the watercraft 10 with the joystick 26. Besides, great deceleration of the watercraft 10, for instance, is enabled by operating the watercraft 10 with the joystick 26. As a result, it is possible to enhance the operability of the watercraft 10 with the joystick 26.

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.

Each of the marine propulsion devices 1a and 1b may be of a type including an internal combustion engine. In the example embodiments described above, the remote controller 25 may be omitted. In other words, the watercraft operating system 100 may be configured to control the output of each marine propulsion device 1a, 1b only by operating the joystick 26.

The thrust levels may be set as two-stage thrust levels. In the two-stage thrust levels, switching between the limiting mode and the non-limiting mode may be made whenever the thrust selector 27 is operated. The thrust levels may be set as three-stage thrust levels, four-stage thrust levels, or six- or more-stage thrust levels.

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.