BOAT CONTROL SYSTEM AND BOAT

Abstract

A boat control system includes first and second boat propulsion devices each turnable about a steering axis and having overlapping turning ranges, a controller, an operator, and a sensor to detect steering angles of the first and second boat propulsion devices. When an operation is accepted by the operator, the controller is configured or programmed to perform a pattern determination process to determine a turning pattern in which the first and second boat propulsion devices do not interfere with each other based on a current angle relationship between the steering angles of the first and second boat propulsion devices and a target angle relationship corresponding to the operation accepted by the operator, and to perform a steering angle change process to change the relationship between the steering angles of the first and second boat propulsion devices to the target angle relationship.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2024-006629 filed on Jan. 19, 2024. The entire contents of this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The technologies disclosed herein relate to boat control systems and boats.

2. Description of the Related Art

A system for controlling the movement of a boat is known and includes a plurality of boat propulsion devices and a controller that controls the thrust and steering angle of each of the plurality of boat propulsion devices. For example, a system for controlling the respective steering angles and shift states of two boat propulsion devices so that the steering angles and shift states correspond to a selected boat operation mode has been proposed (see JP 2010-195388 A and JP 2018-079742 A).

Two boat propulsion devices may be located close to each other, and in such a case, a problem may occur in that the propeller of the first boat propulsion device may interfere with the second boat propulsion device.

SUMMARY OF THE INVENTION

Example embodiments of the present invention disclose technologies that can solve one or more of the above-mentioned problems.

A boat control system according to an example embodiment of the present invention includes a first boat propulsion device and a second boat propulsion device each turnable about a steering axis and having overlapping turning ranges, a controller configured or programmed to control an output and a steering angle of the first boat propulsion device and the second boat propulsion device, an operator to accept operations, and a sensor to detect steering angles of the first boat propulsion device and the second boat propulsion device. When an operation is accepted by the operator, the controller is configured or programmed to perform a pattern determination process to determine a turning pattern in which the first boat propulsion device and the second boat propulsion device do not interfere with each other based on a current angle relationship between the steering angle of the first boat propulsion device and the steering angle of the second boat propulsion device detected by the sensor and a target angle relationship corresponding to the operation accepted by the operator, and a steering angle change process to change the relationship between the steering angle of the first boat propulsion device and the steering angle of the second boat propulsion device to the target angle relationship by turning at least one of the first boat propulsion device and the second boat propulsion device according to the turning pattern.

The technologies disclosed herein can be implemented in various example embodiments, including, e.g., boats, control devices provided on the boats, control methods for the boats, computer programs for implementing functions or methods of the devices, and non-transitory recording media including the computer programs, among other example embodiments.

According to the technologies disclosed herein, it is possible to prevent interference of the propeller of one of the first boat propulsion device and the second boat propulsion device with the other propeller.

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 schematically illustrating a boat according to a first example embodiment of the present invention.

FIG. 2 is a side view schematically illustrating a configuration of a first outboard motor according to the first example embodiment of the present invention.

FIG. 3 is a front view of a configuration of a joystick device according to the first example embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a boat control system according to the first example embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating the control of an outboard motor by a joystick according to the first example embodiment of the present invention.

FIG. 6 is a flowchart showing a flow of the interference prevention process according to the first example embodiment of the present invention.

FIG. 7 is a schematic diagram showing the steering of the outboard motor by the interference prevention process according to the first example embodiment of the present invention.

FIG. 8 is a flowchart showing a flow of an interference prevention process according to a second example embodiment of the present invention.

FIG. 9 is a schematic diagram showing the steering of the outboard motor by the interference prevention process according to the second example embodiment of the present invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

A first example embodiment of the present invention is explained with reference to FIGS. 1 through 8. As shown in FIGS. 1 and 4, the boat 1A of the first example embodiment includes a hull 10, a first outboard motor 100P (a boat propulsion device, an example of the first boat propulsion device), a second outboard motor 100S (a boat propulsion device, an example of the second boat propulsion device), an operator 200 that accepts operation requests to steer the boat 1A, a controller 300 configured or programmed to control the thrust and steering angle of the outboard motors 100P, 100S, a position sensor 260 to detect the position of the hull 10, and an azimuth sensor 270 to detect the turning of the hull 10. The outboard motors 100P, 100S, the operator 200, the controller 300, the position sensor 260, the azimuth sensor 270, and the steering angle sensor 280 are elements of the boat control system 400A.

FIG. 1 and other figures described below show arrows representing each direction with respect to the position of the boat 1A. More specifically, each figure shows arrows representing the front direction (FRONT), rear direction (REAR), left direction (LEFT), right direction (RIGHT), upper direction (UPPER), and lower direction (LOWER), respectively. The front-rear direction, left-right direction, and upper-lower (vertical) direction are orthogonal to each other.

The hull 10 of the boat 1A is for occupants to ride. As shown in FIG. 1, the hull 10 includes a pilot seat 12.

The outboard motors 100P, 100S are attached to the stern of the hull 10 to produce thrust to propel the hull 10. As shown in FIG. 1, the first outboard motor 100P is located on the port side of the hull 10, and the second outboard motor 100S is located on the starboard side of the hull 10. The configuration of the first outboard motor 100P is described in detail below. Since the second outboard motor 100S has the same structure as the first outboard motor 100P, identical elements or parts are marked with identical symbols, and descriptions thereof are omitted. When the elements provided in the first outboard motor 100P and those provided in the second outboard motor 100S are described separately, “P” is added to the end of the sign of the elements provided in the first outboard motor 100P, and “S” is added to the end of the sign of the elements provided in the second outboard motor 100S.

The first outboard motor 100P is attached to the stern of the hull 10 via a bracket 180. The outboard motor 100P is supported by the bracket 180 in a displaceable range from a tilt-down state in which the propeller 140, which is described below, is positioned underwater to a tilt-up state in which the propeller 140 is positioned above the water surface. In the following, the outboard motor 100P in the reference attitude (attitude shown in FIG. 2) will be described unless otherwise noted. The reference attitude is one in which the rotation axis Ad of the drive shaft 124, which is described below, extends in the upper-lower direction and the rotation axis Ap of the propeller shaft 142 extends in the front-rear direction.

As shown in FIG. 2, the outboard motor 100P includes an upper unit 110 attached to the hull 10 via the bracket 180, a lower unit 130 arranged below the upper unit 110, and a steering mechanism 160P interposed between the upper unit 110 and the lower unit 130.

The upper unit 110 includes a cowl 112, an upper case 114, an engine 120, a drive shaft 124, and an electronic control unit (ECU) 190P, as shown in FIG. 2.

The cowl 112 is a housing located on top of the outboard motor 100P. The upper case 114 is a housing arranged below the cowl 112 and is attached to the hull 10 via the bracket 180.

The engine 120 is a prime mover to generate power to drive the outboard motor 100P and is located inside the cowl 112. The engine 120 includes an engine body 121 and an intake device 125. The engine body 121 has a known configuration including a cylinder block (not shown) provided with a plurality of cylinders (not shown), a piston (not shown) disposed inside each cylinder and reciprocating as a mixture of fuel and air is burned, and a crank shaft 122 rotating as the piston reciprocates. The crank shaft 122 is arranged in an attitude extending in the upper-lower direction as shown in FIG. 2. The intake device 125 has a known configuration including an intake channel 126 that supplies air to the inside of the cylinder block, a throttle valve 127P provided in the intake channel 126, and a throttle actuator 128P that controls the opening (throttle opening) of the throttle valve 127P. The throttle actuator 128P includes, e.g., an electric motor. The throttle actuator 128P operates the throttle valve 127P to change the throttle opening. The change in throttle opening changes the flow rate of air supplied to the inside of the cylinder block, thus changing the output of the engine 120 (rotational speed of the crank shaft 122). The throttle actuator 128P is communicatively connected to the ECU 190P.

The drive shaft 124 is a rod-shaped member, connected to the lower end of the crank shaft 122 and positioned in an attitude in which its rotation axis Ad extends in the upper-lower direction. The drive shaft 124 rotates along with the rotation of the crank shaft 122. Most of the drive shaft 124 is located inside the cowl 112 and the upper case 114. The lower end of the drive shaft 124 protrudes downward from the upper case 114 and extends into the interior of the lower unit 130.

The ECU 190P is located inside the cowl 112. The ECU 190P includes a processor such as a central processing unit (CPU) and a storage device such as read only memory (ROM) and random access memory (RAM). The storage device stores various programs and data to control the outboard motor 100P.

The lower unit 130 includes a lower case 132, a propeller 140, a propeller shaft 142, and a shift mechanism 150P, as shown in FIG. 2.

The lower case 132 is a housing arranged below the upper case 114.

The propeller 140 is a rotating body including a plurality of blades and generates thrust by rotating. The propeller shaft 142 is a rod-shaped member and is arranged in an attitude extending in the front-rear direction. The rear end of the propeller shaft 142 protrudes outside the lower case 132, and the remaining portion is housed within the lower case 132. The propeller 140 is attached to the rear end of the propeller shaft 142. As the propeller shaft 142 rotates about the rotation axis Ap, the propeller 140 also rotates.

The shift mechanism 150P is connected to the lower end of the drive shaft 124 and to the front end of the propeller shaft 142. The shift mechanism 150P has a known configuration including, e.g., a forward gear, a backward gear, and a clutch. By switching the engagement of the clutch with the two gears, the direction of rotation transmitted from the drive shaft 124 to the propeller shaft 142 is switched.

The lower unit 130 further includes a shift actuator 152P that switches the shift state of the outboard motor 100P. The shift actuator 152P includes, e.g., an electric motor. The shift actuator 152P is connected to a clutch provided in the shift mechanism 150P and is configured to actuate the clutch to switch the shift state of the outboard motor 100P between the forward movement, backward movement, and neutral states by switching engagement with the forward and the backward gear. The forward movement state is a state in which the clutch engages the forward gear, the rotation of the drive shaft 124 is transmitted to the propeller shaft 142 as forward rotation, and the propeller 140, which rotates in the forward direction with the propeller shaft 142, creates thrust in the forward direction. The backward movement state is a state in which the clutch engages the backward gear, the rotation of the drive shaft 124 is transmitted to the propeller shaft 142 as reverse rotation, and the propeller 140, which rotates in the reverse direction the with propeller shaft 142, produces thrust in the backward direction. The neutral state is a state in which the clutch is not engaged with either the forward gear or the backward gear, so that the rotation of the drive shaft 124 is not transmitted to the propeller shaft 142 and the propeller 140 does not create thrust. The shift actuator 152P is communicatively connected to the ECU 190P.

The steering mechanism 160P changes the direction of the thrust produced by the outboard motor 100P and is configured to rotate the lower unit 130 relative to the upper unit 110. As shown in FIG. 2, for example, the steering mechanism 160P has a known configuration including a pinion 161 that rotates along with the lower unit 130, a turning shaft 162 that is attached to the pinion 161 and through which the drive shaft 124 can be inserted, and a rack 163 that engages the pinion 161 and moves linearly. The steering mechanism 160P is driven by a steering actuator 164P (see also FIG. 4). The steering actuator 164P is a drive to linearly move the rack 163, e.g., the steering actuator 164P includes an electric motor. When the rack 163 is moved linearly by the driving force of the steering actuator 164P, the pinion 161 rotates. This rotation causes the lower unit 130 to rotate around the rotation axis Ad of the drive shaft 124 as the steering axis. In conjunction with this rotation, the propeller shaft 142 rotates about the rotation axis Ad. The steering actuator 164P is communicatively connected to the ECU 190P.

In this specification, the steering angle is defined as follows. As shown in FIG. 5, the steering angle is 0° when the orientation of the lower unit 130 is such that the rotation axis Ap of the propeller shaft 142 is parallel to the centerline C of the hull 10 and the propeller 140 is directed rearward. Then, the clockwise rotation of the lower unit 130, viewed from above, is referred to as positive turning, and the counterclockwise rotation is referred to as negative turning. The rotation angle of the propeller shaft 142 from the 0° steering angle position is referred to as the turning angle. The lower unit 130 can be turned ±180° from the 0° steering angle position, or 180° clockwise and counterclockwise, respectively. In other words, the lower unit 130 can be turned from a steering angle of +180°, back to a steering angle of +00, and then to a steering angle of −180°, and from a steering angle of −180°, back to a steering angle of +0°, and then to a steering angle of +180°. That is, the maximum range (total steering angle) over which the lower unit 130 can be turned is 360°.

The operator 200 is located near the pilot seat 12 and accepts operation requests from the user to control the movement of the hull 10. The operator 200 includes a steering wheel 210, shift/throttle levers 220P, 220S, and a joystick device 230, as shown in FIGS. 1 and 4.

The steering wheel 210 accepts operations by the user to direct the turning direction of the hull 10 and is configured to be rotatable. As shown in FIG. 4, a steering sensor 212 is connected to the steering wheel 210. The steering sensor 212 outputs a steering signal indicating the direction and angle of rotation of the steering wheel 210.

The shift/throttle levers 220P, 220S accept operations by the user of the boat to instruct the magnitude of thrust and shift state switching of the two outboard motors 100P, 100S, respectively. The shift/throttle levers 220P, 220S can be moved forward and backward from the neutral position. As shown in FIG. 4, throttle sensors 222P, 222S are connected to the shift/throttle levers 220P, 220S, respectively. The throttle sensors 222P, 222S output throttle signals indicating the operating direction and amount of operation of the shift/throttle levers 220P, 220S, respectively.

The joystick device 230 includes a rod-shaped joystick 232 that accepts operations by the user to control the movement of the hull 10 and a joystick base 234 that supports the joystick 232 in a tiltable and twistable manner, as shown in FIG. 3 (an example of a mode switching device). The joystick 232 is urged by a spring or other force source to automatically return to the default position (where the joystick 232 is upright) when no operating force is applied. The joystick 232 can be tilted forward, backward, leftward, rightward, and diagonally from the default position, and can be operated by twisting clockwise and counterclockwise, and can be tilted while twisting.

The joystick base 234 includes a joystick button 240, a stay point button 241, a drift point button 242, and a fish point button 243. The joystick button 240 is used to switch the boat operation mode between the normal boat operation mode, in which the steering wheel 210 and the shift/throttle levers 220P, 220S are used to control the boat, and the joystick mode, in which the joystick device 230 is used to control the boat. The stay point button 241, the drift point button 242, and the fish point button 243 are buttons to transition to the set point mode described below.

The joystick base 234 further includes a joystick sensor 250 connected to the joystick 232 (see FIG. 4). The joystick sensor 250 outputs joystick signals indicating the tilt direction and tilt amount (e.g., tilt angle) and the twist direction and twist amount (e.g., twist angle) of the joystick 232. The joystick sensor 250 further outputs an operation signal indicating that any of the buttons 240, 241, 242, 243 has been pushed.

The position sensor 260 detects the position of the hull 10. The position sensor 260 may be a Global Navigation Satellite System (GNSS) receiver, such as the Global Positioning System (GPS). The position sensor 260 detects the position of the hull 10 and outputs a position signal indicating the position of the hull 10.

The azimuth sensor 270 detects the azimuth of the hull 10. The azimuth sensor 270 includes, e.g., an inertial measurement unit (IMU). The azimuth sensor 270 detects the azimuth of the hull 10 and outputs an azimuth signal indicating the azimuth of the hull 10.

The steering angle sensor 280 (an example of a sensor) separately detects the steering angle of the first outboard motor 100P and the steering angle of the second outboard motor 100S. The steering angle sensor 280 detects the steering angle of each outboard motor 100P, 100S and outputs a steering angle signal indicating the steering angle of each outboard motor 100P, 100S.

The controller 300 includes, e.g., a CPU, a multi-core CPU, and a programmable device (e.g., Field Programmable Gate Array (FPGA), Programmable Logic Device (PLD)). The controller 300 controls the operation of the hull 10. In other words, the controller 300 controls the magnitude and direction of the thrust of the outboard motors 100P, 100S, respectively, according to the operations accepted by the operator 200.

The controller 300 includes a storage device. The storage device includes, e.g., ROM, RAM, hard disk drive (HDD), and solid-state drive (SDD). The storage device stores various programs and data and is used as a work area or data storage area when executing various processes. For example, a computer program for executing the interference prevention process described below is stored in the storage device. This computer program is provided, e.g., in a computer-readable recording medium such as a CD-ROM, DVD-ROM, or USB memory (not shown), or it can be obtained from an external device (e.g., a server in the cloud) via a communication interface (not shown) and stored in a storage device in a form that can be operated on the boat control system 400A.

The controller 300 is communicatively connected to the ECUs 190P, 190S, the position sensor 260, the azimuth sensor 270, the steering sensor 212, the throttle sensors 222P, 222S, and the joystick sensor 250.

The controller 300 obtains the position and speed of the hull 10 by receiving position signals from the position sensor 260. The controller 300 obtains the azimuth of the hull 10 by receiving azimuth signals from the azimuth sensor 270.

The controller 300 receives steering signals from the steering sensor 212, throttle signals from the throttle sensors 222P, 222S, and joystick signals and operation signals from the joystick sensor 250. Based on these signals, the controller 300 outputs command signals to the ECUs 190P, 190S. The ECU 190P outputs command signals to the throttle actuator 128P, the shift actuator 152P, and the steering actuator 164P according to the command signals from the controller 300. The ECU 190S outputs command signals to the throttle actuator 128S, the shift actuator 152S, and the steering actuator 164S according to the command signal from the controller 300.

In this example embodiment, the controller 300 sets the boat operation mode to the normal boat operation mode by default. The normal boat operation mode is a mode in which the boat is primarily operated using the steering wheel 210 and the shift/throttle levers 220P, 220S.

In the normal boat operation mode, the controller 300 receives steering signals from the steering sensor 212 and throttle signals from the throttle sensors 222P, 222S. Based on these signals, the controller 300 outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S via the ECUs 190P, 190S.

For example, the controller 300 outputs a command signal corresponding to the operating direction of the shift/throttle lever 220P to the shift actuator 152P. Based on the received command signal, the shift actuator 152P activates the clutch of the shift mechanism 150P to switch the engagement of the clutch with respect to the forward gear and the backward gear. As a result, the shift state of the first outboard motor 100P is switched among the forward movement state, the backward movement state, and the neutral state. Similarly, the controller 300 outputs a command signal corresponding to the operating direction of the shift/throttle lever 220S to the shift actuator 152S. Based on the received command signal, the shift actuator 152S activates the clutch of the shift mechanism 150S to switch the engagement of the clutch with respect to the forward gear and the backward gear. As a result, the shift state of the second outboard motor 100S is switched among the forward movement state, the backward movement state, and the neutral state.

The controller 300 also outputs a command signal corresponding to the operating amount of the shift/throttle lever 220P to the throttle actuator 128P. The throttle actuator 128P changes the opening of the throttle valve 127P based on the received command signal. This changes the rotation speed of the crank shaft 122, which in turn changes the rotation speed of the propeller shaft 142 and the propeller 140, thus changing the magnitude of the thrust produced by the first outboard motor 100P. Similarly, the controller 300 outputs a command signal corresponding to the operating amount of the shift/throttle lever 220S to the throttle actuator 128S. The throttle actuator 128S changes the opening of the throttle valve 127S based on the received command signal. This changes the magnitude of the thrust produced by the second outboard motor 100S.

The controller 300 outputs command signals corresponding to the direction and amount of rotation of the steering wheel 210 to the steering actuators 164P, 164S via the ECUs 190P, 190S. The steering actuator 164P controls the steering mechanism 160P based on the received command signals to change the direction of the lower unit 130, i.e., the steering angle of the first outboard motor 100P. This changes the direction of the thrust of the first outboard motor 100P. Similarly, the steering actuator 164S controls the steering mechanism 160S based on the received command signal to change the direction of the lower unit 130, i.e., the steering angle of the second outboard motor 100S. This changes the direction of the thrust of the second outboard motor 100S. In this way, the azimuth of the hull 10 is controlled.

For example, when the steering wheel 210 is turned to the left from the neutral position, the controller 300 outputs a command signal to the steering actuators 164P, 164S to turn the lower units 130 of the two outboard motors 100P, 100S clockwise from the 0° turning angle position. This causes the hull 10 to turn to the left. When the steering wheel 210 is turned to the right from the neutral position, the controller 300 outputs a command signal to the steering actuators 164P, 164S to turn the lower units 130 of the two outboard motors 100P, 100S counterclockwise from the 0° turning angle position. This causes the hull 10 to turn to the right.

When the joystick device 230 receives an operation to switch the joystick mode from off to on (joystick mode start operation), the controller 300 receives an operation signal from the joystick sensor 250 and switches the boat operation mode from the normal boat operation mode to joystick mode. The joystick mode start operation is, e.g., a short press of the joystick button 240 by the user. When the joystick device 230 receives an operation to switch the joystick mode from on to off (joystick mode deactivation operation), the controller 300 receives an operation signal from the joystick sensor 250 and switches the boat operation mode from joystick mode to the normal boat operation mode. The joystick mode deactivation operation is, e.g., a long press of the joystick button 240 by the user.

When the boat 1A is controlled in the joystick mode, the controller 300 receives joystick signals from the joystick sensor 250. Based on these signals, the controller 300 outputs command signals to the throttle actuators 128P, 128S, shift actuators 152P, 152S and steering actuators 164P, 164S via the ECUs 190P, 190S.

For example, when the joystick 232 is tilted, the controller 300 outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S to move the hull 10 in the direction in which the joystick 232 is tilted at a speed corresponding to the amount the joystick 232 is tilted. When the joystick 232 is twisted (rotated), the controller 300 outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S to turn the hull 10 in the direction in which the joystick 232 is twisted at an angular speed corresponding to the amount the joystick 232 is twisted. Based on the output command signals, the magnitude of thrust, the shift state, and the steering angle of the outboard motors 100P, 100S are controlled.

In this system, the set point mode is selected as the boat operation mode. The set point mode includes stay point mode, drift point mode, and fish point mode. The stay point mode holds the position and azimuth of the hull 10, the fish point mode holds the position of the hull 10, and the drift point mode holds the azimuth of the hull 10.

When the boat 1A is controlled in the joystick mode, if the joystick device 230 accepts a press of the stay point button 241 by the user, the controller 300 receives an operation signal from the joystick sensor 250 and switches the boat operation mode to the stay point mode. When the boat 1A is controlled in the stay point mode, if the joystick device 230 accepts a press of the stay point button 241 by the user, the controller 300 receives an operation signal from the joystick sensor 250 and deactivates the stay point mode. The same applies to the fish point mode and the drift point mode.

For example, when the boat 1A is controlled in the stay point mode, the controller 300 receives signals from the azimuth sensor 270 and the position sensor 260 to obtain the current position and azimuth of the hull 10, and outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S to hold the hull 10 in that position and azimuth. When boat 1A is controlled in the fish point mode, the controller 300 receives signals from the position sensor 260 to obtain the current position of the hull 10 and outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S to hold the hull 10 in that position. When boat 1A is controlled in the drift point mode, the controller 300 receives signals from the azimuth sensor 270 to obtain the current azimuth of the hull 10 and outputs command signals to the throttle actuators 128P, 128S, the shift actuators 152P, 152S, and the steering actuators 164P, 164S to hold the hull 10 in that azimuth. The magnitude of thrust, shift state, and steering angle of the outboard motors 100P, 100S are controlled based on the output command signals.

As shown in FIGS. 1 and 5, the first outboard motor 100P and the second outboard motor 100S are arranged so that the turning ranges of the outboard motors (or the turning ranges of the propeller 140) overlap each other. Specifically, there is an overlapping area H where the rotation range EP of the propeller 140 of the first outboard motor 100P and the rotation range ES of the propeller 140 of the second outboard motor 100S overlap each other (see FIG. 5 and FIG. 7 below). Thus, e.g., if the second outboard motor 100S is turned when the propeller 140 of the first outboard motor 100P is located within the overlapping area H, the propeller 140 of the first outboard motor 100P will interfere with the second outboard motor 100S (e.g., the propeller 140 of the second outboard motor 100S and the portion opposite the propeller 140 (the lower case 132)). Conversely, if the first outboard motor 100P is turned when the propeller 140 of the second outboard motor 100S is located within the overlapping area H, the propeller 140 of the second outboard motor 100S will interfere with the first outboard motor 100P (e.g., the propeller 140 of the first outboard motor 100P or the portion opposite the propeller 140 (the lower case 132)).

The interference prevention process prevents interference between the first outboard motor 100P and the second outboard motor 100S when at least one of the first outboard motor 100P and the second outboard motor 100S is turned. FIG. 6 is a flowchart showing a flow of the interference prevention process.

As shown in FIG. 6, the controller 300 determines whether there is a joystick mode start operation (S110). This determination in S110 is based on the presence or absence of an operation signal from the joystick sensor 250, as described above. If the controller 300 determines that there is no joystick mode start operation (S110: N), it stands by and continues the normal boat operation mode in which the outboard motors 100P, 100S are controlled according to the operation of the steering wheel 210 (S200). If the controller 300 determines that there is a joystick mode start operation (S110: Y), it switches the boat operation mode from the normal boat operation mode to the joystick mode.

Next, the controller 300 determines whether or not the joystick 232 is operated (S120). The determination is based on the joystick signal received from the joystick sensor 250. If the controller 300 determines that there is no operation of the joystick 232 (S120: N), it stands by without executing control over the outboard motors 100P, 100S.

If the controller 300 determines that there is operation of the joystick 232 (S120: Y), it further determines whether there is a difference between the current angle relationship and the target angle relationship (S130). The current angle relationship is the relationship between the steering angle of the first outboard motor 100P and the steering angle of the second outboard motor 100S at the current time (when the joystick device 230 accepts the operation of the joystick 232). The controller 300 can determine the current steering angle of each outboard motor 100P, 100S based on the steering angle signal from the steering angle sensor 280. The target angle relationship is a relationship between the target steering angle of the first outboard motor 100P and the target steering angle of the second outboard motor 100S corresponding to the operation of the joystick 232 accepted by the joystick device 230. No difference between the current angle relationship and the target angle relationship means, e.g., that the current steering angle of the first outboard motor 100P matches the target steering angle and that the current steering angle of the second outboard motor 100S matches the target steering angle. The difference between the current angle relationship and the target angle relationship means, e.g., at least one of that the current steering angle of the first outboard motor 100P does not match the target steering angle and that the current steering angle of the second outboard motor 100S does not match the target steering angle.

If the controller 300 determines that there is no difference between the current angle relationship and the target angle relationship (S130: N), it returns to S120 without executing control of the outboard motors 100P, 100S. On the other hand, if the controller 300 determines that there is a difference between the current angle relationship and the target angle relationship (S130: Y), it further determines whether there is a possibility of interference between the first outboard motor 100P and the second outboard motor 100S when the first outboard motor 100P and the second outboard motor 100S are turned from the current angle relationship to the target angle relationship (S140). For example, the controller 300 determines that there is a possibility of interference if the turning pattern from the current angle relationship to the target angle relationship is a pattern in which at least one of the propellers 140 of the first outboard motor 100P and the second outboard motor 100S enters the overlapping area H. The determination of S140 can be based on the current angle relationship and the target angle relationship.

If the controller 300 determines that there is no possibility of interference (S140: N), it turns the first outboard motor 100P and the second outboard motor 100S from the current angle relationship to the target angle relationship without particularly limiting the steering angle range (S210) and proceeds to S170. For example, when the joystick 232 is tilted forward, as shown in FIG. 5, the current steering angle of the first outboard motor 100P and the current steering angle of the second outboard motor 100S are both 0°. If the joystick 232 is tilted forward diagonally to the right (e.g., +20°) in this state, the target steering angle of the propeller 140 of the first outboard motor 100P and the target steering angle of the second outboard motor 100S are both +20°. In such a case, there is no possibility of interference because neither the propeller 140 of the first outboard motor 100P nor the propeller 140 of the second outboard motor 100S enters the overlapping area H in the process of turning from the current angle relationship to the target angle relationship. Therefore, the first outboard motor 100P and the second outboard motor 100S can be brought into the target angle relationship without interfering with each other, even without specifically limiting the steering angle range.

If the controller 300 determines that there is a possibility of interference (S140: Y), it determines a turning pattern in which the first outboard motor 100P and the second outboard motor 100S do not interfere with each other based on the current angle relationship and the target angle relationship. This process is an example of the pattern determination process. Specifically, the controller 300 limits the steering angle range for one outboard motor of the first outboard motor 100P and the second outboard motor 100S to prohibit it from entering the overlapping area H and turns the other outboard motor so that the current steering angle matches the target steering angle without limiting the steering angle range (S150). The target steering angle of the other outboard motor is the steering angle at which the other outboard motor does not enter the overlapping area H. If the one outboard motor has already entered the overlapping area H in the current angle relationship, the controller 300 executes the process of S150 after turning the one outboard motor outside the overlapping area H. During the execution of the process of S150, the controller 300 may bring the steering angle of the one outboard motor closer to the target steering angle to the extent that it does not enter the overlapping area H.

After the current steering angle of the other outboard motor matches the target steering angle, the controller 300 releases the limitation on the steering angle range for the one outboard motor and causes the one outboard motor to turn so that the current steering angle matches the target steering angle (S160), and then proceeds to S170. In the process of S160, the one outboard motor is allowed to enter the overlapping area H, but the other outboard motor is located outside the overlapping area H, so the first outboard motor 100P and the second outboard motor 100S do not interfere with each other. The processes in S150 and S160 are examples of the steering angle change process.

In S170, the controller 300 determines whether the joystick mode has been deactivated. If an operation signal is received from the joystick sensor 250 accompanying the joystick mode deactivation operation by the user, the controller 300 judges that the joystick mode has been deactivated and switches the boat operation mode to the normal boat operation mode. If the operation signal associated with the joystick mode deactivation operation is not received, the controller 300 judges that the joystick mode has not been deactivated and returns to S120 to repeat the process.

As described above, the boat 1A of this example embodiment includes the hull 10 and the boat control system 400A. The boat control system 400A includes the first outboard motor 100P and the second outboard motor 100S, which are configured to be able to turn about a steering axis and whose turning ranges overlap each other, the controller 300 that controls the thrust and steering angle of the first outboard motor 100P and the second outboard motor 100S, and the operator 200 that accepts the operation to move the hull 10 and outputs the operation signal to the controller 300, and the steering angle sensor 280 that detects the steering angle of each outboard motor 100P, 100S and outputs the steering angle signal indicating the steering angle of each outboard motor 100P, 100S.

When the joystick mode start operation is accepted by the operator 200, the controller 300 determines a turning pattern in which the first outboard motor 100P and the second outboard motor 100S do not interfere with each other based on the current angle relationship and the target angle relationship detected by the steering angle sensor 280 (FIG. 6, S140: Y, pattern determination process). Next, the controller 300 changes the steering angle of the first outboard motor 100P and the steering angle of the second outboard motor 100S to the target angle relationship by turning at least one of the first outboard motor 100P and the second outboard motor 100S according to the turning pattern (FIG. 6, S150, S160: Y, steering angle change process).

FIG. 7 is a schematic diagram showing the steering of the outboard motor by the interference prevention process. The left side of FIG. 7 shows the angle relationship (current steering angle relationship) between the steering angle of the first outboard motor 100P and the steering angle of the second outboard motor 100S when the joystick 232 of the joystick device 230 is tilted to the left side. At this time, the current steering angle of the first outboard motor 100P is backward diagonally left (e.g. −135°) and the current steering angle of the second outboard motor 100S is forward diagonally left (e.g. −45°), resulting in the hull 10 moving laterally to the left.

Next, the joystick 232 of the joystick device 230 is tilted from the left side to the right side. Then the target steering angle of the first outboard motor 100P becomes forward diagonal to the right (e.g., +45°), and the target steering angle of the second outboard motor 100S becomes backward diagonal to the right (e.g., +135°) (see right side of FIG. 7). Here, in the process of turning from the current angle relationship to the target angle relationship, both the first outboard motor 100P and the second outboard motor 100S may interfere with each other because the propeller 140 enters the overlapping area H.

Therefore, e.g., the steering angle range is limited for the first outboard motor 100P to prohibit the first outboard motor 100P from entering the overlapping area H. On the other hand, for the second outboard motor 100S, the steering angle range is not limited and the second outboard motor 100S is allowed to turn so that the current steering angle matches the target steering angle (see the central view in FIG. 7, S150). At this time, the first outboard motor 100P does not enter the overlapping area H so the steering angle of the second outboard motor 100S can be set to the target steering angle without interference between the first outboard motor 100P and the second outboard motor 100S. Next, the limitation of the steering angle range is released for the first outboard motor 100P, and the first outboard motor 100P is made to turn so that the current steering angle matches the target steering angle (see right side view of FIG. 7, S160). This prevents interference between the first outboard motor 100P and the second outboard motor 100S when the joystick 232 of the joystick device 230 is tilted from the left side to the right side. As a result, the hull 10 moves laterally to the right.

Although not described in detail, interference between the first outboard motor 100P and the second outboard motor 100S can be prevented when the joystick 232 is reversely operated (when the joystick is tilted from the right side to the left side when the joystick 232 is tilted from the front side to the rear side, and when the joystick 232 is tilted from the rear side to the front side), and also when the joystick 232 is rotated or twisted.

FIG. 8 is a flowchart showing the flow of the interference prevention process in a second example embodiment. In this second example embodiment, a portion of the interference control process differs from the first example embodiment, but the rest of the process is the same, so the explanation of the same process is omitted.

As shown in FIG. 8, when the controller 300 determines that there is a possibility of interference (S140: Y), one outboard motor of the first outboard motor 100P and the second outboard motor 100S is turned such that the propeller 140 of the one outboard motor moves away from the other outboard motor (S350). It is preferable that the one outboard motor to be turned first is the outboard motor in which the position of the propeller 140 at the target steering angle is farther from the other outboard motor than the position of the propeller 140 at the current steering angle. In this case, the propeller 140 of the one outboard motor does not enter the overlapping area H so the first outboard motor 100P and the second outboard motor 100S do not interfere with each other. After the steering angle of the one outboard motor reaches the target steering angle, the other outboard motor is turned so that the steering angle of the other outboard motor matches the target steering angle.

FIG. 9 shows a schematic diagram showing the steering of the outboard motor by the interference prevention process. The left side of FIG. 9 shows the angle relationship (current steering angle relationship) between the steering angle of the first outboard motor 100P and the steering angle of the second outboard motor 100S when the joystick 232 of the joystick device 230 is tilted to the left side (the same as the left side of FIG. 7).

Next, the joystick 232 of the joystick device 230 is tilted from the left side to the right side. Then, the first outboard motor 100P turns in a rotational direction (counterclockwise on paper) in which the propeller 140 of the first outboard motor 100P moves away from the second outboard motor 100S (see the center view in FIG. 9). At this time, the propeller 140 of the first outboard motor 100P does not enter the overlapping area H so there is no interference between the first outboard motor 100P and the second outboard motor 100S. Next, the second outboard motor 100S is turned so that the steering angle of the second outboard motor 100S matches the target steering angle (see right side view in FIG. 9). At this time, the propeller 140 of the first outboard motor 100P is located outside the overlapping area H so there is no interference between the first outboard motor 100P and the second outboard motor 100S.

Although not described in detail, interference between the first outboard motor 100P and the second outboard motor 100S can be prevented in the same manner when the joystick 232 is tilted from the right side to the left side, when the joystick 232 is tilted from the front side to the rear side, or when the joystick 232 is tilted from the rear side to the front side.

The technologies disclosed herein are not limited to the above-described example embodiments and may be modified in various ways without departing from the gist of the present invention, including the following modifications.

In the above example embodiments, the outboard motors 100P, 100S are outboard motors driven by an engine, but the outboard motors can also be electric outboard motors driven by a motor.

In the above example embodiments, both the first outboard motor 100P and the second outboard motor 100S are turned in the steering angle change process, but only one of the first and second outboard motors may be turned in the steering angle change process.

In each example embodiment, an example in which the controller 300 executes the pattern determination process and the steering angle change process when the joystick mode start operation is performed is explained (see e.g., FIGS. 6 and 8), but it is not limited to this. For example, the controller 300 may execute the pattern determination process and the steering angle change process when the stay point mode start operation is performed.

The turning patterns in which the first boat propulsion device and the second boat propulsion device do not interfere with each other are not limited to the patterns listed in each of the above example embodiments. The turning pattern may be, e.g., a pattern in which the propellers are turned so that they are outside the overlapping area for both the first boat propulsion device and the second boat propulsion device, then the steering angle of one boat propulsion device is set to the target steering angle, and then the steering angle of the other boat propulsion device is set to the target steering angle.

In the above example embodiments, the controller is exemplified by the controller 300, which is a single unit that controls the output (the throttle actuator 128P and the like) and the steering angle (the steering actuator 164P and the like) of each outboard motor 100P, 100S. However, the controller may include a plurality of units that are separate from each other. For example, the controller may include an engine controller that controls the output of each outboard motor 100P, 100S, a steering controller that controls the turning of each outboard motor 100P, 100S, and a control unit that determines the turning pattern.

In each of the above example embodiments, the boat 1A is equipped with two outboard motors 100P, 100S, but the boat may be equipped with three or more outboard motors. In each of the above example embodiments, the boat propulsion devices are outboard motors 100P, 100S, but the boat propulsion devices may be inboard motors, inboard and outboard motors, or jet propulsion units.

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.

Claims

1. A boat control system for controlling a boat including a hull, the boat control system comprising: a first boat propulsion device and a second boat propulsion device each turnable about a steering axis and having overlapping turning ranges;a controller configured or programmed to control an output and a steering angle of the first boat propulsion device and the second boat propulsion device;an operator to accept operation requests; anda sensor to detect the steering angles of the first boat propulsion device and the second boat propulsion device; whereinwhen an operation is accepted by the operator, the controller is configured or programmed to perform: a pattern determination process to determine a turning pattern in which the first boat propulsion device and the second boat propulsion device do not interfere with each other based on a current angle relationship between the steering angle of the first boat propulsion device and the steering angle of the second boat propulsion device detected by the sensor and a target angle relationship corresponding to the operation accepted by the operator; anda steering angle change process to change the relationship between the steering angle of the first boat propulsion device and the steering angle of the second boat propulsion device to the target angle relationship by turning at least one of the first boat propulsion device and the second boat propulsion device according to the turning pattern.

2. The boat control system according to claim 1, wherein the first boat propulsion device and the second boat propulsion device are capable of turning turn 180 degrees or more about the steering axis.

3. The boat control system according to claim 1, wherein the first boat propulsion device and the second boat propulsion device are capable of turning ±360 degrees about the steering axis.

4. The boat control system according to claim 1, wherein the turning pattern turns the first boat propulsion device in a rotational direction in which a propeller of the first boat propulsion device moves away from the second boat propulsion device.

5. The boat control system according to claim 2, wherein the turning pattern turns the first boat propulsion device in a rotational direction in which a propeller of the first boat propulsion device moves away from the second boat propulsion device.

6. The boat control system according to claim 3, wherein the turning pattern turns the first boat propulsion device in a rotational direction in which a propeller of the first boat propulsion device moves away from the second boat propulsion device.

7. The boat control system according to claim 4, wherein the turning pattern turns the second boat propulsion device in a rotational direction in which the propeller of the second boat propulsion device moves closer to the first boat propulsion device.

8. The boat control system according to claim 5, wherein the turning pattern turns the second boat propulsion device in a rotational direction in which the propeller of the second boat propulsion device moves closer to the first boat propulsion device.

9. The boat control system according to claim 6, wherein the turning pattern is a pattern that turns the second boat propulsion device in a rotational direction in which the propeller of the second boat propulsion device moves closer to the first boat propulsion device.

10. The boat control system according to claim 1, wherein the turning pattern prohibits the turning of the first boat propulsion device into the overlapping area between the turning range of the first boat propulsion device and the turning range of the second boat propulsion device, and permits the turning of the first boat propulsion device into the overlapping area after a propeller of the second boat propulsion device moves through the overlapping area.

11. The boat control system according to claim 2, wherein the turning pattern is a pattern that prohibits the turning of the first boat propulsion device into the overlapping area between the turning range of the first boat propulsion device and the turning range of the second boat propulsion device and permits the turning of the first boat propulsion device into the overlapping area after a propeller of the second boat propulsion device moves through the overlapping area.

12. The boat control system according to claim 3, wherein the turning pattern prohibits the turning of the first boat propulsion device into the overlapping area between the turning range of the first boat propulsion device and the turning range of the second boat propulsion device, and permits the turning of the first boat propulsion device into the overlapping area after a propeller of the second boat propulsion device moves through the overlapping area.

13. The boat control system according to claim 1, wherein the operator includes a joystick; andthe controller is configured or programmed to perform the pattern determination process and the steering angle change process when the operation on the joystick is accepted.

14. The boat control system according to claim 2, wherein the operator includes a joystick; andthe controller is configured or programmed to perform the pattern determination process and the steering angle change process when the operation on the joystick is accepted.

15. The boat control system according to claim 3, wherein the operator includes a joystick; andthe controller is configured or programmed to perform the pattern determination process and the steering angle change process when the operation on the joystick is accepted.

16. The boat control system according to claim 1, wherein the first boat propulsion device and the second boat propulsion device each include an upper portion fixed to the hull and a lower portion including a propeller and rotatable about the steering axis with respect to the upper portion.

17. The boat control system according to claim 2, wherein the first boat propulsion device and the second boat propulsion device each include an upper portion fixed to the hull and a lower portion including a propeller and rotatable about the steering axis with respect to the upper portion.

18. The boat control system according to claim 3, wherein the first boat propulsion device and the second boat propulsion device each include an upper portion fixed to the hull and a lower portion including a propeller and rotatable about the steering axis with respect to the upper portion.

19. A boat comprising: a hull; andthe boat control system according to claim 1.

20. A boat comprising: a hull; andthe boat control system according to claim 2.