VESSEL STEERING SYSTEM FOR DOCKING AND VESSEL STEERING METHOD FOR DOCKING

Abstract

A system for steering a vessel includes a plurality of propulsion devices including a first propulsion device and a second propulsion device, a first actuator connected to the first propulsion device to change a steering angle of the first propulsion device, a second actuator connected to the second propulsion device to change a steering angle of the second propulsion device, and a controller configured or programmed to alternate between a port side movement control and a starboard side movement control.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vessel steering systems for docking vessels, and vessel steering methods for docking vessels.

SUMMARY OF THE INVENTION

A system for steering a vessel according to an example embodiment of the present invention includes a plurality of propulsion devices including a first propulsion device and a second propulsion device, a first actuator connected to the first propulsion device to change a steering angle of the first propulsion device, a second actuator connected to the second propulsion device to change a steering angle of the second propulsion device, and a controller configured or programmed to alternate between a port side movement control and a starboard side movement control.

In an example embodiment of present invention, when the port side movement control is performed, the controller is configured or programmed to: set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are each oriented slanted with respect to a back-and-forth direction of the vessel and control a propulsive force of the first propulsion device and a propulsive force of the second propulsion device such that a net force of the propulsive forces of the first and second propulsion devices is oriented in a port side direction; and when the starboard side movement control is performed, the controller is configured or programmed to: set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are each oriented slanted with respect to the back-and-forth direction of the vessel, and control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a starboard side direction.

In an example embodiment of present invention, the controller is configured or programmed to alternate between the port side movement control and the starboard side movement control between a start pointing and an end pointing of a transit line, the controller is configured or programmed to determine whether the vessel is located on a port side or a starboard side of the transit line, when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to perform the starboard side movement control, and when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to perform the port side movement control.

In an example embodiment of present invention, when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a first port side docking lane or a second port side docking lane, the first port side docking lane and the second port side docking lane are each virtual docking lanes on the port side of the transit line, the first port side docking lane is located closer to the transit line than the second port side docking lane in a lateral direction perpendicular to the transit line, when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a first starboard side docking lane or a second starboard side docking lane, the first starboard side docking lane and the second starboard side docking lane are each virtual docking lanes on the starboard side of the transit line, and the first starboard side docking lane is located closer to the transit line than the second starboard side docking lane in the lateral direction perpendicular to the transit line.

In an example embodiment of present invention, when the controller determines that the vessel is located in the first port side docking lane, the controller is configured or programmed to perform a first starboard side movement control in which the net force acting on the vessel is at a first angle with respect to a center line of the vessel, when the controller determines that the vessel is located in the second port side docking lane, the controller is configured or programmed to perform a second starboard side movement control in which the net force acting on the vessel is at a second angle with respect to the center line of the vessel, the second angle being greater than the first angle, when the controller determines that the vessel is located in the first starboard side docking lane, the controller is configured or programmed to perform a first port side movement control in which the net force acting on the vessel is at a third angle with respect to the center line of the vessel, and when the controller determines that the vessel is located in the second starboard side docking lane, the controller is configured or programmed to perform a second port side movement control in which the net force acting on the vessel is at a fourth angle with respect to the center line of the vessel, the fourth angle being greater than the third angle.

In an example embodiment of present invention, the controller is configured or programmed to set a magnitude of the net force of the second starboard side movement control to be larger than a magnitude of the net force of the first starboard side movement control, and the controller is configured or programmed to set a magnitude of the net force of the second port side movement control to be larger than a magnitude of the net force of the first port side movement control.

In an example embodiment of present invention, each of the first port side docking lane, the second port side docking lane, the first starboard side docking lane, and the second starboard side docking lane is less than 0.5 times a width of the vessel.

In an example embodiment of present invention, the port side movement control is a port side transverse movement control in which the net force is perpendicular to the transit line, and the starboard side movement control is a starboard side transverse movement control in which the net force is perpendicular to the transit line.

In an example embodiment of present invention, the controller is configured or programmed to set a magnitude of the net force of the starboard side movement control based on a distance of the vessel from the transit line, and the controller is configured or programmed to set a magnitude of the net force of the port side movement control based on a distance of the vessel from the transit line.

In an example embodiment of present invention, the controller is configured or programmed to determine whether the vessel is located on the port side or the starboard side of the transit line based on a location of the vessel including a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel.

In an example embodiment of present invention, the controller is configured or programmed to determine whether the vessel is located on the port side or the starboard side of the transit line at a predetermined interval of time.

In an example embodiment of present invention, when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a port side docking lane which is a virtual docking lane on the port side of the transit line, the port side docking lane is spaced away from the transit line by a first predetermined distance, when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a starboard side docking lane which is a virtual docking lane on the starboard side of the transit line, and the starboard side docking lane is spaced away from the transit line by a second predetermined distance that is the same as or different from the first predetermined distance.

In an example embodiment of present invention, when the controller determines that the vessel is located on the port side of the transit line after having crossed the transit line, the controller is configured or programmed to perform the starboard side movement control when the vessel is a predetermined distance from the transit line, and when the controller determines that the vessel is located on the starboard side of the transit line after having crossed the transit line, the controller is configured or programmed to perform the port side movement control when the vessel is a predetermined distance from the transit line.

In an example embodiment of present invention, the starting point and the ending point are determined based on map data or sensor data.

In an example embodiment of present invention, when the port side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a rearward port side direction, and when the starboard side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a rearward starboard side direction.

In an example embodiment of present invention, when the port side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a forward port side direction, and when the starboard side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a forward starboard side direction.

In an example embodiment of present invention, when the port side movement control is performed, a line of action of the net force of the propulsive forces of the first and second propulsion devices extends through a center of gravity of the vessel, and when the starboard side movement control is performed, a line of action of the net force of the propulsive forces of the first and second propulsion devices extends through the center of gravity of the vessel.

In an example embodiment of present invention, when the port side movement control is performed, the controller is configured or programmed to set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are oriented opposite to each other, and when the starboard side movement control is performed, the controller is configured or programmed to set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are oriented opposite to each other.

In an example embodiment of present invention, the controller is configured or programmed to set a magnitude of the net force based on a user input and/or a disturbance value detected by a disturbance sensor.

In an example embodiment of present invention, when the controller determines that the vessel is located in the first portside docking lane, the controller is configured or programmed to perform a first starboard movement control in which the net force is set to a first net force, when the controller determines that the vessel is located in the second portside docking lane, the controller is configured or programmed to perform a second starboard movement control in which the net force is set to a second net force that is larger in magnitude than the first net force, when the controller determines that the vessel is located in the first starboard side docking lane, the controller is configured or programmed to perform a first portside movement control in which the net force is set to a third net force, and when the controller determines that the vessel is located in the second starboard side docking lane, the controller is configured or programmed to perform a second portside movement control in which the net force is set to a fourth net force that is larger in magnitude than the third net force.

In an example embodiment of present invention, the controller is configured or programmed to set a width of each of the first portside docking lane, the second portside docking lane, the first starboard side docking lane, and the second starboard side docking lane based on a user input and/or a disturbance value detected by a disturbance sensor.

In an example embodiment of present invention, the first propulsion device includes a first outboard motor, and the second propulsion device includes a second outboard motor.

A method executed by a controller to steer a vessel including a first propulsion device and a second propulsion device according to an example embodiment of the present invention includes alternatingly performing a port side movement control and a starboard side movement control between a start pointing and an end pointing of a transit line of the vessel.

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 top view of a vessel according to an example embodiment of the present invention.

FIG. 2 is a side view of a left propulsion device.

FIG. 3 is a schematic diagram showing a configuration of a vessel steering system according to an example embodiment of the present invention.

FIG. 4A is a diagram showing propulsive forces in a back-and-forth movement control.

FIG. 4B is a diagram showing propulsive forces in a back-and-forth movement control.

FIG. 5A is a diagram showing the propulsive forces in a starboard transverse movement control.

FIG. 5B is a diagram showing the propulsive forces in a portside transverse movement control.

FIG. 6 is a diagram showing the propulsive forces in a turning mode.

FIG. 7A is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 7B is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 7C is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 7D is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 8A is a diagram showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

FIG. 8B is a diagram showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

FIG. 9A is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 9B is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 9C is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 9D is a diagram showing propulsive forces in a zig-zag moving mode according to an example embodiment of the present invention.

FIG. 10A is a diagram showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

FIG. 10B is a diagram showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

FIG. 11 is a flowchart showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

FIG. 12 is a flowchart showing a zig-zag moving mode used to dock a vessel according to an example embodiment of the present invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the present invention will be hereinafter explained with reference to the attached drawings. FIG. 1 is a top view of a vessel 1 according to an example embodiment of the present invention. A vessel steering system 2 according to an example embodiment of the present invention is provided on the vessel 1. As shown in FIG. 1, the vessel steering system 2 includes a plurality of propulsion devices 3a and 3b. The propulsion devices 3a and 3b are outboard motors, for example. Specifically, the vessel 1 includes a left propulsion device 3a and a right propulsion device 3b. It should be noted that in the following explanation, front, rear, right, left, up, and down directions are defined as meaning the front, rear, right, left, up, and down directions of the vessel 1, respectively.

The left and right propulsion devices 3a and 3b are attached to the stern of the vessel 1. The left and right propulsion devices 3a and 3b are aligned in the width direction of the vessel 1. Specifically, the left propulsion device 3a is disposed on the left side of a center line C1 extending in a back-and-forth direction of the vessel 1, and the right propulsion device 3b is disposed on the right side of the center line C1. Each propulsion device 3a and 3b generates a propulsive force to propel the vessel 1.

FIG. 2 is a side view of the left propulsion device 3a. The left propulsion device 3a includes an engine 10a, a driveshaft 11, a propeller shaft 12, a shift mechanism 13, an engine cowl 14, a housing 15, and a bracket 16.

The engine 10a generates the propulsive force to propel the vessel 1. The engine 10a is disposed inside the engine cowl 14. The engine 10a includes a crankshaft 17 that extends in a vertical direction. The driveshaft 11 is connected to the crankshaft 17 and extends downward from the engine 10a. The propeller shaft 12 extends in a direction intersecting with the driveshaft 11 and in the back-and-forth direction. The propeller shaft 12 is connected to the driveshaft 11 through the shift mechanism 13. A propeller 18 is connected to the propeller shaft 12.

The housing 15 is disposed directly below the engine cowl 14. The driveshaft 11, the propeller shaft 12, and the shift mechanism 13 are disposed inside the housing 15. The shift mechanism 13 switches the rotational direction of power to be transmitted from the driveshaft 11 to the propeller shaft 12. The shift mechanism 13 includes a forward moving gear 19, a rearward moving gear 20, and a clutch 21. The forward moving gear 19 and the rearward moving gear 20 are meshed with a bevel gear 22. The bevel gear 22 is attached to the driveshaft 11. The clutch 21 selectively causes either the forward moving gear 19 or the rearward moving gear 20 to be engaged with the propeller shaft 12. The clutch 21 is movable to a forward moving position, a rearward moving position, and a neutral position.

When set in the forward moving position, the clutch 21 causes the forward moving gear 19 to be engaged with the propeller shaft 12. Accordingly, the rotation of the driveshaft 11 is transmitted to the propeller shaft 12 so as to rotate the propeller shaft 12 in a forward moving direction. When set in the rearward moving position, the clutch 21 causes the rearward moving gear 20 to be engaged with the propeller shaft 12. Accordingly, the rotation of the driveshaft 11 is transmitted to the propeller shaft 12 so as to rotate the propeller shaft 12 in a rearward moving direction. When set in the neutral position, the clutch 21 causes both the forward moving gear 19 and the rearward moving gear 20 to be disengaged from the propeller shaft 12. Therefore, the rotation of the driveshaft 11 is not transmitted to the propeller shaft 12.

The left propulsion device 3a includes a shifter 23 and a shift actuator 24a. The shifter 23 is connected to the shift mechanism 13. The shifter 23 actuates the shift mechanism 13. More specifically, the shifter 23 is connected to the clutch 21. When driven by the shift actuator 24a, the shifter 23 moves the clutch 21 to one of the forward moving position, the rearward moving position, and the neutral position. The shift actuator 24a is connected to the shifter 23. The shift actuator 24a drives the shifter 23. The shift actuator 24a includes, for instance, an electric motor. The shift actuator 24a drives the shifter 23 so as to switch the clutch 21 to one of the forward moving position, the rearward moving position, and the neutral position.

The bracket 16 attaches the left propulsion device 3a to the vessel 1. The left propulsion device 3a is detachably fixed to the stern of the vessel 1 through the bracket 16. The bracket 16 includes a steering shaft 25. The left propulsion device 3a is supported by the bracket 16 while being rotatable about the steering shaft 25.

FIG. 3 is a schematic diagram showing a configuration of the vessel steering system 2. The right propulsion device 3b has a similar configuration to the left propulsion device 3a. For example, as shown in FIG. 3, the right propulsion device 3b includes an engine 10b and a shift actuator 24b. The engine 10b and the shift actuator 24b in the right propulsion device 3b have similar configurations to the engine 10a and the shift actuator 24a in the left propulsion device 3a.

As shown in FIG. 3, the vessel steering system 2 includes a left steering actuator 26a and a right steering actuator 26b. The left steering actuator 26a is connected to the left propulsion device 3a, and rotates the left propulsion device 3a about the steering shaft 25. Thus, the left steering actuator 26a changes the steering angle of the left propulsion device 3a. The left steering actuator 26a includes, for instance, a hydraulic cylinder. Alternatively, the left steering actuator 26a may include an electric cylinder or an electric motor.

The right steering actuator 26b is connected to the right propulsion device 3b, and changes the steering angle of the right propulsion device 3b. The right steering actuator 26b has a similar configuration to the left steering actuator 26a.

As shown in FIG. 3, the vessel steering system 2 includes a remote control 30, a steering 31, a joystick 32, and a controller 33, a position detector 38, and a disturbance sensor 39.

The remote control 30 includes a first operator 34 and a second operator 35. The first operator 34 is operated by a user to control the left propulsion device 3a. The first operator 34 includes, for instance, a lever. The first operator 34 is movable to a forward moving position, a rearward moving position, and a neutral position. The remote control 30 transmits a signal indicating an operation of the first operator 34 to the controller 33.

The second operator 35 is operated by the user to control the right propulsion device 3b. The second operator 35 has a similar configuration to the first operator 34. The remote control 30 transmits the signal indicating an operation of the first operator 34 to the controller 33. The remote control 30 transmits a signal indicating an operation of the second operator 35 to the controller 33.

The steering 31 includes, for instance, a steering wheel. The steering 31 is operable by the user to control the steering angles of the left and right propulsion devices 3a and 3b. The steering 31 is movable to a left turn position, a right turn position, and a neutral position. The steering 31 transmits a signal indicating an operation of the steering 31 to the controller 33.

The joystick 32 is operable in a tiltable manner. The joystick 32 is movable in front, rear, right, and left directions and oblique directions therebetween. The joystick 32 is movable 360 degrees in all the directions about a rotational axis Ax1 of the joystick 32. Additionally, the joystick 32 is operable by being twisted about the rotational axis Ax1.

The joystick 32 transmits a signal indicating the position of the joystick 32 to the controller 33. The position of the joystick 32 indicates the tilt direction and the tilt amount of the joystick 32. Additionally, the position of the joystick 32 indicates the twist direction and the twist amount of the joystick 32.

The position detector 38 can include a GNSS receiver, for example. The GNSS receiver includes an antenna to receive a signal(s) from a GNSS satellite(s) and a processing circuit to determine a position of the vessel 1 (e.g., a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel) based on the signal(s) received by the antenna. The position detector 38 receives a GNSS signal(s) transmitted from a GNSS satellite(s), and performs positioning on the basis of the GNSS signal(s). GNSS is a general term for satellite positioning systems, such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System, e.g., MICHIBIKI), GLONASS, Galileo, BeiDou, and the like. The position detector 38 is connected to the controller 33 and transmits a signal indicating the position of the vessel 1 to the controller 33. The position detector 38 can be attached to the hull of the vessel 1, as shown in FIG. 4, for example.

Instead of or in addition to the GNSS receiver, the position detector 38 may include any other type of device, such as a LiDar sensor. Additionally, the position detector 38 may include one or more cameras for positioning. When objects serving as characteristic points exist in the environment that is traveled by the vessel 1, the position of the vessel 1 can be estimated with a high accuracy based on data that is acquired with the LiDar sensor or cameras and an environment map that is previously recorded in a storage device (e.g., memory 37). The LiDAR sensor or cameras may be used together with the GNSS receiver. By correcting or complementing position data based on the GNSS signal(s) using the data acquired by the LiDAR sensor or cameras, it becomes possible to identify the position of the vessel 1 with a higher accuracy. Furthermore, the position detector 38 may complement the position data by using a signal from an inertial measurement unit (IMU). The IMU can measure tilts and minute motions of the vessel 1. By complementing the position data based on the GNSS signal using the data acquired by the IMU, the positioning performance can be improved.

The disturbance sensor 39 can include one or more of a wind speed sensor to detect a force and a direction of a wind acting of the vessel 1, and a water current sensor to detect a force and a direction of a water current acting of the vessel 1. The disturbance sensor 39 is connected to the controller 33 and transmits a signal(s) indicating the detected force and the direction of the wind acting of the vessel 1 and/or the detected force and the direction of the water current acting of the vessel 1 to the controller 33. In an example embodiment, the disturbance sensor 39 can be attached to the hull of the vessel 1, as shown in FIG. 4, however, this is non-limiting and the disturbance sensor 39 can be attached to another location on the vessel 1 or may be external to the vessel 1.

The controller 33 includes a processor 36 and a memory 37. The memory 37 includes a volatile memory such as a RAM and a non-volatile memory such as a ROM. The controller 33 may include an auxiliary storage such as an HDD or an SSD. The memory 37 stores programs and data to control the left and right propulsion devices 3a and 3b and the left and right steering actuators 26a and 26b. The processor 36 may be a CPU (Central Processing Unit), for instance, and may be configured or programmed to execute processes to control the left and right propulsion devices 3a and 3b and the left and right steering actuators 26a and 26b in accordance with the stored programs.

The controller 33 is configured or programmed to control the left and right propulsion devices 3a and 3b and the left and right steering actuators 26a and 26b based on the signals transmitted thereto from the steering 31, the remote control 30, and the joystick 32. More specifically, the controller 33 is configured or programmed to control the direction and the magnitude of the propulsive force of the left propulsion device 3a in accordance with the position of the first operator 34. The controller 33 is configured or programmed to control the shift actuator 24a in accordance with the position of the first operator 34. Accordingly, the clutch 21 of the shift mechanism 13 is switched among the forward moving position, the rearward moving position, and the neutral position. As a result, the direction of the propulsive force of the left propulsion device 3a is switched among forward, rearward, and neutral. The controller 33 is configured or programmed to control the magnitude of the propulsive force of the left propulsion device 3a by, for instance, controlling the throttle opening degree of the engine 10a.

The controller 33 also is configured or programmed to control the direction and the magnitude of the propulsive force of the right propulsion device 3b in accordance with the position of the second operator 35. The controller 33 is configured or programmed to control the shift actuator 24b in accordance with the position of the second operator 35. Accordingly, similarly to the left propulsion device 3a, the direction of the propulsive force of the right propulsion device 3b is switched among forward, rearward, and neutral. The controller 33 is configured or programmed to control the magnitude of the propulsive force of the right propulsion device 3b by, for instance, controlling the throttle opening degree of the engine 10b.

The controller 33 is configured or programmed to control the left and right steering actuators 26a and 26b in accordance with the position of the steering 31. Accordingly, the steering angles of the left and right propulsion devices 3a and 3b are controlled. As a result, the turn direction of the vessel 1 is controlled.

The controller 33 is configured or programmed to control the left and right propulsion devices 3a and 3b and the left and right steering actuators 26a and 26b in accordance with the position of the joystick 32. The controller 33 is configured or programmed to control the propulsive forces and the steering angles of the left and right propulsion devices 3a and 3b such that the vessel 1 performs a translational motion in a direction corresponding to the tilt direction of the joystick 32.

More specifically, when the tilt direction of the joystick 32 is the back-and-forth direction, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in a back-and-forth movement control. FIGS. 4A and 4B are diagrams showing propulsive forces to be generated in the back-and-forth movement control. As shown in FIG. 4A, when the tilt direction of the joystick 32 is the front direction, the controller 33 sets the propulsion devices 3a and 3b to be oriented parallel to the back-and-forth direction. Additionally, the controller 33 sets both the propulsion devices 3a and 3b to a forward moving state (i.e., the clutch 21 is in the forward moving position), and sets the magnitudes of the propulsive forces of the propulsion devices 3a and 3b to be equal. Accordingly, the vessel 1 is moved in the forward direction. When the tilt direction of the joystick 32 is the rear direction, the controller 33 sets the propulsion devices 3a and 3b to be oriented parallel to the back-and-forth direction. As shown in FIG. 4B, the controller 33 sets the propulsion devices 3a and 3b to a rearward moving state (i.e., the clutch 21 is in the rearward moving position), and sets the magnitudes of the propulsive forces of the propulsion devices 3a and 3b to be equal. Accordingly, the vessel 1 is moved in the rear direction.

When the tilt direction of the joystick 32 includes a vector related to a right-and-left direction, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in a transverse movement control. FIG. 5A is a diagram showing propulsive forces to be generated in the starboard transverse movement control, and FIG. 5B is a diagram showing propulsive forces to be generated in the portside transverse movement control.

As shown in FIGS. 5A and 5B, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. The controller 33 is configured or programmed to control the propulsive forces of the left and right propulsion devices 3a and 3b such that a net force F3 is oriented in a direction corresponding to the tilt direction of the joystick 32. The net force F3 is a net force of a propulsive force F1 of the left propulsion device 3a and a propulsive force F2 of the right propulsion device 3b. The above-described predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1.

More specifically, as shown in FIG. 5A, when the tilt direction of the joystick 32 is the right direction, the controller 33 sets the left propulsion device 3a to the forward moving state and the right propulsion device 3b to the rearward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the right direction. As a result, the vessel 1 is moved in the right direction.

As shown in FIG. 5B, when the tilt direction of the joystick 32 is the left direction, contrary to the above-described settings, the controller 33 sets the left propulsion device 3a to the rearward moving state and the right propulsion device 3b to the forward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the left direction. As a result, the vessel 1 is moved in the left direction.

When the joystick 32 is twisted in a neutral position, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b in a turning mode. In the turning mode, the controller 33 is configured or programmed to control the propulsive forces and the steering angles of the propulsion devices 3a and 3b such that the vessel 1 turns the bow thereof in a direction corresponding to the twist direction of the joystick 32. FIG. 6 is a diagram showing propulsive forces to be generated in the turning mode. As shown in FIG. 6, the controller 33 sets the steering angles of the left and right propulsion devices 3a and 3b such that the left and right propulsion device 3a and 3b are oriented parallel to the back-and-forth direction. The controller 33 sets the propulsive forces of the left and right propulsion devices 3a and 3b to be directionally opposite to each other.

More specifically, when the twist direction of the joystick 32 is the clockwise direction, the controller 33 sets the left propulsion device 3a to the forward moving state and the right propulsion device 3b to the rearward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the vessel 1 turns the bow thereof in the clockwise direction.

When the twist direction of the joystick 32 is the counterclockwise direction, contrary to the above-described settings, the controller 33 sets the left propulsion device 3a to the rearward moving state and the right propulsion device 3b to the forward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the vessel 1 turns the bow thereof in the counterclockwise direction.

As discussed above with respect to FIGS. 4A and 4B, the controller 33 can control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in a back-and-forth movement control. For example, as shown in FIG. 4A, the controller 33 can set both the propulsion devices 3a and 3b to a forward moving state, and set the magnitudes of the propulsive forces of the propulsion devices 3a and 3b to be equal. As shown in FIG. 4B, the controller 33 can set both the propulsion devices 3a and 3b to a rearward moving state, and set the magnitudes of the propulsive forces of the propulsion devices 3a and 3b to be equal. However, in certain situations (e.g., during docking), the back-and-forth movement control may not be suitable vessel movements due to the minimum thrust that can be produced by the propulsion devices 3a and 3b. For example, the back-and-forth movement control may not be suitable for docking the vessel in a forward or rearward direction because even when the propulsion devices 3a and 3b are operated at a minimum revolution per minute (RPM) (e.g., 600 PRM) such that the propulsion devices 3a and 3b each produce a minimum thrust, the propulsion devices 3a and 3b still generate too much thrust to allow the vessel to approach a dock at a suitable speed. In other words, the back-and-forth movement control may not be suitable for docking the vessel in a forward or rearward direction because even when the propulsion devices 3a and 3b are each controlled to generate a minimum thrust, the resulting thrust may cause the vessel to approach the dock too quickly.

In order to address these shortcomings of the back-and-forth movement control, the controller 33 is configured or programmed to be able to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in a zigzag moving mode including a rearward zigzag moving mode and a forward zigzag moving mode, as discussed in detail below. FIGS. 7A-7D are diagrams showing propulsive forces to be generated in a rearward zigzag moving mode, and FIGS. 9A-9D are diagrams showing propulsive forces to be generated in a forward zigzag moving mode.

In an example embodiment, the controller 33 is configured or programmed to be able to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in the rearward zigzag moving mode to perform a rearward docking control (e.g., an autonomous rearward docking control), and the controller 33 is configured or programmed to be able to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in the forward zigzag moving mode to perform a forward docking control (e.g., an autonomous forward docking control). However, this is non-limiting, and the controller 33 is configured or programmed to be able to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in the rearward zigzag moving mode and the forward zigzag moving mode in order to navigate the vessel through a narrow channel, a crowded marina, and/or adverse conditions (e.g., high wind and/or current) in order to achieve improved movement control of the vessel.

As shown in FIGS. 7A and 7B, the controller 33 can set the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 can set the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and set the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. Accordingly, the net force F3 is oriented in the rearward portside direction, wherein a portion of the rearward thrust of the propulsion device 3a which is the rearward moving state is counteracted by the forward thrust of the propulsion device 3b which is in the forward moving state. As a result, the vessel 1 can be moved in the rearward-portside direction in a controlled manner and at a speed slower than a speed attainable using the back-and-forth movement control (for example, FIG. 4B in which the controller 33 sets both the propulsion devices 3a and 3b to a rearward moving state). For example, the vessel 1 can be moved in the rearward-portside direction at a speed slower than a speed of the vessel when the controller 33 sets both the propulsion devices 3a and 3b to a minimum thrust and a rearward moving state. In this way, as shown in FIGS. 7A and 7B, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a rearward-port side movement control.

As shown in FIGS. 7C and 7D, the controller 33 can set the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. Accordingly, the net force F3 is oriented in the rearward-starboard direction, wherein a portion of the rearward thrust of the propulsion device 3b which is in the rearward moving state is counteracted by the forward thrust of the propulsion device 3a which is in the forward moving state. As a result, the vessel 1 can be moved in the rearward-starboard direction in a controlled manner and at a speed slower than any speed attainable using the back-and-forth movement control (for example, FIG. 4B in which the controller 33 sets both the propulsion devices 3a and 3b to a rearward moving state). For example, the vessel 1 can be moved in the rearward-starboard direction at a speed slower than a speed of the vessel when the controller 33 sets both the propulsion devices 3a and 3b to a minimum thrust and a rearward moving state. In this way, as shown in FIGS. 7C and 7D, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a rearward-starboard side movement control.

As shown in FIG. 8A, the controller 33 is configured or programmed to perform the rearward zigzag moving mode by alternating between performing a rearward-port side movement control (e.g., as shown in FIGS. 7A and 7B) and performing a rearward-starboard side movement control (e.g., as shown in FIGS. 7C and 7D). For example, FIG. 8A illustrates an example in which the controller 33 executes a rearward zigzag mode in order to dock the vessel 1 at a dock D.

FIGS. 8B and 11 show the detailed steps by which the controller 33 is configured or programmed to perform the rearward zigzag moving mode. As shown in FIGS. 8B and 11, in step S11-1, the controller 33 is configured or programmed to set a transit line TL, which is a line that connects a starting point SP of the vessel and a desired ending point EP (e.g., a location at which the vessel is to be docked). In an example embodiment, the starting point SP and ending point EP are determined based on previously obtained GPS coordinates. However, this is non-limiting, and the starting point SP and ending point EP can be determined based on local map data of the environment, sensor data collected by a docking system (e.g., LiDAR), or another method.

In step S11-2, the controller 33 is configured or programmed to determine whether the vessel is located on a portside or a starboard side of the transit line TL. For example, the controller 33 can determine whether the vessel is located on the portside or the starboard side of the transit line TL based on whether a center of gravity of the vessel is located on the portside or the starboard side of the transit line TL (e.g., using the position detector 38). However, this is non-limiting, and the controller 33 can also determine whether the vessel is located on the portside or the starboard side of the transit line TL based on whether a geometric center of the vessel or another location of the vessel is located on the portside or the starboard side of the transit line TL, for example.

If in step S11-2 the controller 33 determines that the vessel is located on the portside of the transit line TL, then the process proceeds to step S11-3. On the other hand, if in step S11-2 the controller 33 determines that the vessel is located on the starboard side of the transit line TL, then the process proceeds to step S11-4.

In step S11-3, the controller 33 determines whether the vessel is located in a first portside docking lane PDL1, a second portside docking lane PDL2, or a third portside docking lane PDL3, as shown in FIG. 8B, for example. The first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 are each virtual docking lanes on the portside of the transit line TL. As shown in FIG. 8B, the first portside docking lane PDL1 is located closest to the transit line TL (e.g., adjacent to the transit line TL), the second portside docking lane PDL2 is located farther from the transit line TL than the first portside docking lane PDL1 in a lateral direction (perpendicular to the transit line TL), and the third portside docking lane PDL3 is located farther from the transit line TL than the second portside docking lane PDL2 in the lateral direction. In an example embodiment, each of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can be set to a predetermined width in the lateral direction. For example, the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can have widths that are individually set and that can be the same as or different from each other. For example, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can each empirically be set based on information including the size of the vessel, the weight of the vessel, the hull shapes of the vessel, and/or a typical wind and/or current force of the environment in which the vessel is operating. For example, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can each be set based on an input(s) from a user/vessel operator (e.g., using a graphical user interface). In this way, the controller 33 is configured or programmed to set the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 based on a user input.

Additionally, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can each be set based on a disturbance value(s) (e.g., a wind force value and/or a current force value) detected by the disturbance sensor 39. For example, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can be set to a first width when a disturbance value detected by the disturbance sensor 39 is less than a disturbance value threshold (e.g., predetermined wind force value and/or a predetermined current force value), and set to a second width smaller than the first width when the disturbance value detected by the disturbance sensor 39 is greater than or equal to the disturbance value threshold. In this way, the controller 33 is configured or programmed to set the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 based on a disturbance value detected by the disturbance sensor 39.

In FIGS. 8B and 10B, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 are exaggerated for illustrative purposes. For example, the widths of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can each be less than 0.5 times the width b of the vessel body, can each be less than 0.3 times the width b of the vessel body, or can each be less than 0.1 times the width b of the vessel body. For example, the width of the first portside docking lane PDL1 can be set to 0.2-0.5 m, the width of the second portside docking lane PDL2 can be set to 0.7-1.5 m, and the width of the third portside docking lane can be set to 2-5 m, however, these values are non-limiting examples.

Similarly to step S11-2, in step S11-3, the controller 33 can determine whether the vessel is located in the first portside docking lane PDL1, the second portside docking lane PDL2, or the third portside docking lane PDL3 based on whether a center of gravity, a geometric center of the vessel, or another location of the vessel is located in the first portside docking lane PDL1, the second portside docking lane PDL2, or the third portside docking lane PDL3.

If in step S11-3 the controller 33 determines that the vessel is located in the first portside docking lane PDL1, the process proceeds to step S11-5. If in step S11-3 the controller 33 determines that the vessel is located in the second portside docking lane PDL2, the process proceeds to step S11-6. If in step S11-3 the controller 33 determines that the vessel is located in the third portside docking lane PDL3, the process proceeds to step S11-7.

As discussed above, if in step S11-2 the controller 33 determines that the vessel is located on the starboard side of the transit line TL, then the process proceeds to step S11-4. In step S11-4, the controller 33 determines whether the vessel is located in a first starboard side docking lane SDL1, a second starboard side docking lane SDL2, or a third starboard side docking lane SDL3, as shown in FIG. 8B, for example. The first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 are each virtual docking lanes on the starboard side of the transit line TL. As shown in FIG. 8B, the first starboard side docking lane SDL1 is located closest to the transit line TL (e.g., adjacent to the transit line TL), the second starboard side docking lane SDL2 is located farther from the transit line TL than the first starboard side docking lane SDL1 in a lateral direction (perpendicular to the transit line TL), and the third starboard side docking lane SDL3 is located farther from the transit line TL than the second starboard side docking lane SDL2 in the lateral direction. In an example embodiment, each of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can be set to a predetermined width in the lateral direction. For example, the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can have widths that are individually set and that can be the same as or different from each other. For example, the widths of first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can each empirically be set based on information including the size of the vessel, the weight of the vessel, the hull shapes of the vessel, and/or a typical wind and/or current force of the environment in which the vessel is operating. For example, the widths of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can each be set based on an input(s) from a user/vessel operator (e.g., using a graphical user interface). In this way, the controller 33 is configured or programmed to set the widths of first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 based on a user input.

Additionally, the widths of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can each be set based on a disturbance value(s) (e.g., a wind force value and/or a current force value) detected by the disturbance sensor 39. For example, the widths of first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can be set to a first width when a disturbance value detected by the disturbance sensor 39 is less than a disturbance value threshold, and set to a second width smaller than the first width when the disturbance value detected by the disturbance sensor 39 is greater than or equal to the disturbance value threshold. In this way, the controller 33 is configured or programmed to set the widths of first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 based on a disturbance value detected by the disturbance sensor 39.

In FIGS. 8B and 10B, the widths of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 are exaggerated for illustrative purposes. For example, the widths of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can each be less than 0.5 times the width b of the vessel body, can each be less than 0.3 times the width b of the vessel body, or can each be less than 0.1 times the width b of the vessel body. For example, the width of the first starboard side docking lane SDL1 can be set to 0.2-0.5 m, the width of the second starboard side docking lane SDL2 can be set to 0.7-1.5 m, and the width of the third starboard side docking lane SDL3 can be set to 2-5 m, however, these values are non-limiting examples.

Similarly to step S11-2, in step S11-4, the controller 33 can determine whether the vessel is located in the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3 based on whether a center of gravity, a geometric center of the vessel, or another location of the vessel is located in the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3.

If in step S11-4 the controller 33 determines that the vessel is located in the first starboard side docking lane SDL1, the process proceeds to step S11-8. If in step S11-4 the controller 33 determines that the vessel is located in the second starboard side docking lane SDL2, the process proceeds to step S11-9. If in step S11-4 the controller 33 determines that the vessel is located in the third starboard side docking lane SDL3, the process proceeds to step S11-10.

In example embodiments discussed above, step S11-2, step S11-3, and step S11-4 are performed separately. However, this is non-limiting, and steps S11-2 and S11-3, or steps S11-2 and S11-4, can be performed simultaneously based on a location of a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel. For example, the controller 33 can be configured or programmed to directly determine in which of the first portside docking lane PDL1, the second portside docking lane PDL2, the third portside docking lane PDL3, the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3 the vessel is located (e.g., using the position detector 38).

Next, steps S11-5 through S11-10 will be discussed in detail with respect to FIG. 11.

In step S11-5, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a first rearward-starboard side movement control, as shown in FIG. 7C, for example. In order to perform the first rearward-starboard side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b according to a first ratio that results in the net force F3 acting on the vessel at a first angle A1θ with respect to the center line C1 of the vessel.

In step S11-5, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1. For example, while the vessel may enter the first starboard side docking lane SDL1 as a result of the first rearward-starboard side movement control being performed, the vessel may also enter the second portside docking lane PDL2 due to current and/or wind acting on the vessel in a portside direction.

In step S11-5, if the controller 33 determines that the vessel enters the second portside docking lane PDL2 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), then the process proceeds to step S11-6. On the other hand, if in step S11-5 the controller 33 determines that the vessel enters the first starboard side docking lane SDL1, then the process proceeds to step S11-8.

In step S11-6, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a second rearward-starboard side movement control, as shown in FIG. 7D, for example. In order to perform the second rearward-starboard side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b according to a second ratio that results in the net force F3 acting on the vessel at a second angle A2θ with respect to the center line C1 of the vessel.

In an example embodiment, the second angle A2θ of the second rearward-starboard side movement control (e.g., as shown in FIG. 7D) is greater than the first angle A1θ of the first rearward-starboard side movement control (e.g., as shown in FIG. 7C). In other words, the net force F3 acting on the vessel in the second rearward-starboard side movement control is directed in a more lateral starboard direction than the net force F3 acting on the vessel in the first rearward-starboard side movement control.

In an example embodiment, the controller 33 can set the magnitudes of the propulsion device 3a and the propulsion device 3b such that the net force F3 acting on the vessel in the second rearward-starboard side movement control has a greater magnitude than the net force F3 acting on the vessel in the first rearward-starboard side movement control.

In step S11-6, the controller 33 also monitors the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1. For example, while the vessel may enter the first portside docking lane PDL1 as a result of the second rearward-starboard side movement control being performed, the vessel may also enter the third portside docking lane PDL3 due to current and/or wind acting on the vessel in a portside direction.

In step S11-6, if the controller 33 determines that the vessel enters the third portside docking lane PDL3 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), then the process proceeds to step S11-7. On the other hand, if in step S11-6 the controller 33 determines that the vessel enters the first portside docking lane PDL1, then the process proceeds to step S11-5.

In step S11-7, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the starboard transverse movement control (see FIG. 5A). As discussed above with respect to FIG. 5A, in order to perform the starboard transverse movement control, the controller 33 sets the left propulsion device 3a to the forward moving state and sets the right propulsion device 3b to the rearward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the right direction and the vessel 1 is moved in the right direction. In an example embodiment, the controller 33 can be configured or programmed to set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, based on a lateral distance from the transit line TL. For example, the controller 33 can set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, to increase when a distance between the vessel and the transit line increases and decrease when the distance between the vessel and the transit line decreases. In this way, if the vessel continues to move away from the transit line TL when the vessel is located in the third portside docking lane PDL3 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), the net force F3 oriented in the right direction can be increased to attempt to move the vessel back towards the transit line TL.

In step S11-7, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 (e.g., as a result of the starboard transverse movement control being performed). In step S11-7, if the controller 33 determines that the vessel enters the second portside docking lane PDL2, then the process proceeds to step S11-6.

In step S11-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a first rearward-port side movement control, as shown in FIG. 7A, for example. In order to perform the first rearward-port side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b according to a first ratio that results in the net force F3 acting on the vessel at a first angle A1θ with respect to a center line C1 of the vessel.

In step S11-8, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1. For example, while the vessel may enter the first portside docking lane PDL1 as a result of the first rearward-port side movement control being performed, the vessel may also enter the second starboard docking lane SDL2 due to current and/or wind acting on the vessel in a starboard side direction.

In step S11-8, if the controller 33 determines that the vessel enters the second starboard side docking lane SDL2 (e.g., as a result of current and/or wind acting on the vessel in a starboard side direction), then the process proceeds to step S11-9. On the other hand, if in step S11-8, the controller 33 determines that the vessel enters the first portside docking lane PDL1, then the process proceeds to step S11-5.

In step S11-9, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a second rearward-port side movement control, as shown in FIG. 7B, for example. In order to perform the second rearward-port side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b according to a second ratio that results in the net force F3 acting on the vessel at a second angle A2θ with respect to the center line C1 of the vessel.

In an example embodiment, the second angle A2θ of the second rearward-port side movement control (e.g., as shown in FIG. 7B) is greater than the first angle A1θ of the first rearward-port side movement control (e.g., as shown in FIG. 7A). In other words, the net force F3 acting on the vessel in the second rearward-port side movement control is directed in a more lateral portside direction than the net force F3 acting on the vessel in the first rearward-port side movement control.

In an example embodiment, the controller 33 can set the magnitudes of the propulsion device 3a and the propulsion device 3b such that the net force F3 acting on the vessel in the second rearward-port side movement control has a greater magnitude than the net force F3 acting on the vessel in the first rearward-port side movement control.

In step S11-9, the controller 33 also monitors the location of the vessel to determine if the vessel enters the third starboard side docking lane SDL3 or the first starboard side docking lane SDL1. For example, while the vessel may enter the first starboard side docking lane SDL1 as a result of the second rearward-port side movement control being performed, the vessel may also enter the third starboard side docking lane SDL3 due to current and/or wind acting on the vessel in a starboard side direction.

In step S11-9, if the controller 33 determines that the vessel enters the third starboard side docking lane SDL3 (e.g., as a result of current and/or wind acting on the vessel in a starboard side direction), then the process proceeds to step S11-10. On the other hand, if in step S11-9 the controller 33 determines that the vessel enters the first starboard side docking lane SDL1, then the process proceeds to step S11-8.

In step S11-10, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the portside transverse movement control (see FIG. 5B). As discussed above with respect to FIG. 5B, in order to perform the portside transverse movement control, the controller 33 sets the left propulsion device 3a to the rearward moving state and sets the right propulsion device 3b to the forward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the left direction and the vessel 1 is moved in the left direction. In an example embodiment, the controller 33 can be configured or programmed to set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, based on a lateral distance from the transit line TL. For example, the controller 33 can set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, to increase when a distance between the vessel and the transit line increases, and to decrease when the distance between the vessel and the transit line decreases. In this way, if the vessel continues to move away from the transit line TL when the vessel is located in the third starboard docking lane SDL3 (e.g., as a result of current and/or wind acting on the vessel in a starboard direction), the net force F3 oriented in the left direction can be increased to attempt to move the vessel back towards the transit line TL.

In step S11-10, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 (e.g., as a result of the portside transverse movement control being performed). In step S11-10, if the controller 33 determines that the vessel enters the second starboard side docking lane PDL3, then the process proceeds to step S11-9.

As discussed above, the controller 33 can be configured or programmed to determine a location of the vessel based on a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel. The controller 33 can be configured or programmed to determine the location of the vessel at a predetermined interval of time (e.g., every 0.1 seconds or every 0.5 seconds) during steps S11-2 through S11-10 of the rearward zigzag moving mode, for example.

In an example embodiment of the present invention, the controller 33 can be configured or programmed to control the propulsion devices 3a and 3b such that the magnitude of the net force F3 generated in each of the first rearward-starboard side movement control in step S11-5, the second rearward-starboard side movement control in step S11-6, the starboard transverse movement control in step S11-7, the first rearward-port side movement control in step S11-8, the second rearward-port side movement control in step S11-9, and the portside transverse movement control in step S11-10 are generated/set based on an input(s) from a user/vessel operator. For example, the user/vessel operator can set magnitude/force value(s) for the net force F3 to be generated in each of the first rearward-starboard side movement control in step S11-5, the second rearward-starboard side movement control in step S11-6, the starboard transverse movement control in step S11-7, the first rearward-port side movement control in step S11-8, the second rearward-port side movement control in step S11-9, and the portside transverse movement control in step S11-10 before the rearward zigzag moving mode is executed (e.g., using a graphical user interface), and these value(s) can be saved in the memory 37 of the controller 33. In this way, the controller 33 is configured or programmed to set a magnitude of the net force F3 based on a user input.

In an example embodiment of the present invention, the controller 33 can be configured or programmed to control the propulsion devices 3a and 3b such that the magnitude of the net force F3 generated in each of the first rearward-starboard side movement control in step S11-5, the second rearward-starboard side movement control in step S11-6, the starboard transverse movement control in step S11-7, the first rearward-port side movement control in step S11-8, the second rearward-port side movement control in step S11-9, and the portside transverse movement control in step S11-10 are generated/set based on a disturbance value(s) (e.g., a wind force value and/or a current force value) detected by the disturbance sensor 39. For example, the magnitude of the net force F3 to be generated in each of the first rearward-starboard side movement control in step S11-5, the second rearward-starboard side movement control in step S11-6, the starboard transverse movement control in step S11-7, the first rearward-port side movement control in step S11-8, the second rearward-port side movement control in step S11-9, and the portside transverse movement control in step S11-10 can be multiplied by a disturbance factor (e.g., 1.1, 1.5, or 2, for example) when the disturbance value detected by the disturbance sensor 39 is greater than or equal to a disturbance value threshold. In this way, the controller 33 is configured or programmed to set a magnitude of the net force F3 based on a disturbance value detected by the disturbance sensor 39.

An example of the rearward zigzag moving mode will now be described with respect to FIGS. 8B and 11. In step S11-1, the controller 33 sets the transit line TL, which is a line that connects the starting point SP of the vessel and a desired ending point EP (e.g., at which the vessel is to be docked).

In step S11-2, the controller 33 determines that the vessel is located on the starboard side of the transit line TL at time t0, and the process proceeds to step S11-4. In step S11-4, the controller 33 determines that the vessel is located in the first starboard side docking lane SDL1 at time t0, and the process proceeds to step S11-8. In step S11-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-port side movement control (FIG. 7A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t1, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S11-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-starboard side movement control (FIG. 7C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t2, the controller 33 determines that the vessel has entered the second portside docking lane PDL2 (e.g., due to current and/or wind acting on the vessel in a portside direction). As a result, at time t2, the process proceeds to step S11-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-starboard side movement control (FIG. 7D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At times t3 and t4, the controller 33 determines that the vessel remains in the second portside docking lane PDL2. As a result, at times t3 and t4, the process remains at step S11-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-starboard side movement control (FIG. 7D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t5, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S11-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-starboard side movement control (FIG. 7C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t6, the controller 33 determines that the vessel is located in the first starboard side docking lane SDL1, and the process proceeds to step S11-8. In step S11-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-port side movement control (FIG. 7A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t7, the controller 33 determines that the vessel has entered the second starboard side docking lane SDL2 (e.g., due to current and/or wind acting on the vessel in a starboard side direction). As a result, at time t7, the process proceeds to step S11-9 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-port side movement control (FIG. 7B), and monitor the location of the vessel to determine if the vessel enters the third starboard docking lane SDL3 or the first starboard docking lane SDL1.

At time t8, the controller 33 determines that the vessel has entered the third starboard docking lane SDL3 (e.g., due to a strong current and/or wind acting on the vessel in a starboard side direction). As a result, at time t8, the process proceeds to step S11-10 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the portside transverse movement control (see FIG. 5B), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 as a result of the portside transverse movement control being performed.

At time t9, the controller 33 determines that the vessel has entered the second starboard side docking lane SDL2. As a result, at time t9, the process proceeds to step S11-9 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-port side movement control (FIG. 7B), and monitor the location of the vessel to determine if the vessel enters the third starboard docking lane SDL3 or the first starboard docking lane SDL1.

At time t10, the controller 33 determines that the vessel has entered the first starboard side docking lane SDL1, and the process proceeds to step S11-8. In step S11-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-port side movement control (FIG. 7A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t11, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S11-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-starboard side movement control (FIG. 7C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t12, the controller 33 determines that the vessel has entered the second portside docking lane PDL2 (e.g., due to current and/or wind acting on the vessel in a portside direction). As a result, at time t12, the process proceeds to step S11-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-starboard side movement control (FIG. 7D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t13, the controller 33 determines that the vessel remains in the second portside docking lane PDL2. As a result, at time t13, the process remains at step S11-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second rearward-starboard side movement control (FIG. 7D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t14, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S11-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first rearward-starboard side movement control (FIG. 7C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t15, the controller 33 determines that the vessel has reached the ending point EP and the process ends.

In example embodiments of the rearward zigzag mode, the first portside docking lane PDL1 and the first starboard side docking lane SDL1 can be located immediately adjacent to the transit line TL. However, this is non-limiting, and the first portside docking lane PDL1 can be spaced away from the transit line TL by a first predetermined distance, and the first starboard side docking lane SDL1 each be spaced away from the transit line TL by a second predetermined distance the same as or different from the first predetermined distance. The first portside docking lane PDL1 being spaced away from transit line TL by the first predetermined distance, and the first starboard side docking lane SDL1 being spaced away from transit line TL by the second predetermined distance, can create a “deadband” surrounding the transit line TL, which can prevent the rearward zigzag mode from transitioning between the first rearward-port side movement control (FIG. 7A) and the first rearward-starboard side movement control (FIG. 7C) at a rate that negatively affects the functionality of the rearward zigzag mode, particularly when the vessel is operating in conditions with no wind or current or substantially no wind or current. For example, the clutch 21 of each of the propulsion devices 3a and 3b can be moved to the neutral position when the vessel is located in the “deadband” surrounding the transit line TL.

In an example embodiment of the present invention, when (in response to) the vessel has crossed the transit line L from the first starboard side docking lane SDL1 to the first portside docking lane PDL1, the controller 33 can be configured or programmed to wait to switch from the first rearward-port side movement control (FIG. 7A) to the first rearward-starboard side movement control (FIG. 7C) until the vessel is a predetermined distance from the transit line TL (when located in the first portside docking lane PDL1). In other words, when the vessel has crossed the transit line L from the first starboard side docking lane SDL1 to the first portside docking lane PDL1, the first starboard side docking lane SDL1 can be modified such that a portion of the first starboard side docking lane SDL1 crosses over to a portside of the transit line TL by a predetermined distance.

Similarly, when the vessel has crossed the transit line L from the first portside docking lane PDL1 to the first starboard side docking lane SDL1, the controller 33 can be configured or programmed to wait to switch from the first rearward-starboard side movement control (FIG. 7C) to the first rearward-port side movement control (FIG. 7A) until the vessel is a predetermined distance from the transit line TL (when located in the first starboard side docking lane SDL1). In other words, when the vessel has crossed the transit line L from the first portside docking lane PDL1 to the first starboard side docking lane SDL1, the first portside docking lane PDL1 can be modified such that a portion of the first portside docking lane PDL1 crosses over to a starboard side of the transit line TL by a predetermined distance.

This functionality can prevent the rearward zigzag mode from transitioning between the first rearward-port side movement control (FIG. 7A) and the first rearward-starboard side movement control (FIG. 7C) at a rate that negatively affects the functionality of the rearward zigzag mode, particularly when the vessel is operating in conditions with no wind or current or substantially no wind or current.

As discussed above, the controller 33 is configured or programmed to be able to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b in a forward zigzag mode. As shown in FIGS. 9A and 9B, the controller 33 can set the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. Accordingly, the net force F3 is oriented in the forward-portside direction, wherein a portion of the forward thrust of the propulsion device 3b which is in the forward moving state is counteracted by the rearward thrust of the propulsion device 3a which is in the rearward moving state. As a result, the vessel 1 can be moved in the forward-portside direction in a controlled manner and at a speed slower than a speed attainable using the back-and-forth movement control (for example, FIG. 4A in which the controller 33 sets both the propulsion devices 3a and 3b to a forward moving state). For example, the vessel 1 can be moved in the forward-portside direction at a speed slower than a speed of the vessel when the controller 33 sets both the propulsion devices 3a and 3b to a minimum trust and a forward moving state. In this way, as shown in FIGS. 9A and 9B, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a forward-port side movement control.

As shown in FIGS. 9C and 9D, the controller 33 can set the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. Accordingly, the net force F3 is oriented in the forward-starboard direction, wherein a portion of the forward thrust of the propulsion device 3a which is in the forward moving state is counteracted by the rearward thrust of the propulsion device 3b which is in the forward moving state. As a result, the vessel 1 can be moved in the forward-starboard direction in a controlled manner and at a speed slower than a speed attainable using the back-and-forth movement control (for example, FIG. 4A in which the controller 33 sets both the propulsion devices 3a and 3b to a forward moving state). For example, the vessel 1 can be moved in the forward-starboard direction at a speed slower than a speed of the vessel when the controller 33 sets both the propulsion devices 3a and 3b to a minimum trust and a forward moving state. In this way, as shown in FIGS. 9C and 9D, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a forward-starboard side movement control.

As shown in FIG. 10A, the controller 33 is configured or programmed to perform the forward zigzag moving mode by alternating between performing a forward-port side movement control (e.g., as shown in FIGS. 9A and 9B) and performing a forward-starboard side movement control (e.g., as shown in FIGS. 9C and 9D). For example, FIG. 10A illustrates an example in which the controller 33 executes a forward zigzag mode in order to dock the vessel 1 at a dock D.

FIGS. 10B and 12 show the detailed steps by which the controller 33 is configured or programmed to perform the forward zigzag moving mode. As shown in FIGS. 10B and 12, in step S12-1, the controller 33 is configured or programmed to set a transit line TL, which is a line that connects a starting point SP of the vessel and a desired ending point EP of the vessel (e.g., a location at which the vessel is to be docked). In an example embodiment, the starting point SP and ending point EP are determined based on previously obtained GPS coordinates. However, this is non-limiting, and the starting point SP and ending point EP can be determined based on local map data of the environment, based on sensor data collected by a docking system (e.g., LiDAR), or another method.

In step S12-2, the controller 33 is configured or programmed to determine whether the vessel is located on a portside or a starboard side of the transit line TL. For example, the controller 33 can determine whether the vessel is located on the portside or the starboard side of the transit line TL based on whether a center of gravity of the vessel is located on the portside or the starboard side of the transit line TL. However, this is non-limiting and the controller 33 can also determine whether the vessel is located on the portside or the starboard side of the transit line TL based on whether a geometric center of the vessel or another location of the vessel is located on the portside or the starboard side of the transit line TL, for example.

If in step S12-2 the controller 33 determines that the vessel is located on the portside of the transit line TL, then the process proceeds to step S12-3. On the other hand, if in step S12-2 the controller 33 determines that the vessel is located on the starboard side of the transit line TL, then the process proceeds to step S12-4.

In step S12-3, the controller 33 determines whether the vessel is located in a first portside docking lane PDL1, a second portside docking lane PDL2, or a third portside docking lane PDL3, as shown in FIG. 10B, for example. The first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 are each virtual docking lanes on the portside of the transit line TL. As shown in FIG. 10B, the first portside docking lane PDL1 is located closest to the transit line TL (e.g., adjacent to the transit line TL), the second portside docking lane PDL2 is located farther from the transit line TL than the first portside docking lane PDL1 in a lateral direction (perpendicular to the transit line TL), and the third portside docking lane PDL3 is located farther from the transit line TL than the second portside docking lane PDL2 in the lateral direction. In an example embodiment, each of the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can be set to a predetermined width in the lateral direction. For example, the first portside docking lane PDL1, the second portside docking lane PDL2, and the third portside docking lane PDL3 can have widths that are individually set and that can be the same as or different from each other. Similarly to step S12-2, in step S12-3, the controller 33 can determine whether the vessel is located in the first portside docking lane PDL1, the second portside docking lane PDL2, or the third portside docking lane PDL3 based on whether a center of gravity, a geometric center of the vessel, or another location of the vessel is located in the first portside docking lane PDL1, the second portside docking lane PDL2, or the third portside docking lane PDL3.

If in step S12-3 the controller 33 determines that the vessel is located in the first portside docking lane PDL1, the process proceeds to step S12-5. If in step S12-3 the controller 33 determines that the vessel is located in the second portside docking lane PDL2, the process proceeds to step S12-6. If in step S12-3 the controller 33 determines that the vessel is located in the third portside docking lane PDL3, the process proceeds to step S12-7.

As discussed above, if in step S12-2 the controller 33 determines that the vessel is located on the starboard side of the transit line TL, then the process proceeds to step S12-4. In step S12-4, the controller 33 determines whether the vessel is located in a first starboard side docking lane SDL1, a second starboard side docking lane SDL2, or a third starboard side docking lane SDL3, as shown in FIG. 10B, for example. The first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 are each virtual docking lanes on the starboard side of the transit line TL. As shown in FIG. 10B, the first starboard side docking lane SDL1 is located closest to the transit line TL (e.g., adjacent to the transit line TL), the second starboard side docking lane SDL2 is located farther from the transit line TL than the first starboard side docking lane SDL1 in a lateral direction (perpendicular to the transit line TL), and the third starboard side docking lane SDL3 is located farther from the transit line TL than the second starboard side docking lane SDL2 in the lateral direction. In an example embodiment, each of the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can be set to a predetermined width in the lateral direction. For example, the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, and the third starboard side docking lane SDL3 can have widths that are individually set and that can be the same as or different from each other. Similarly to step S12-2, in step S12-4, the controller 33 can determine whether the vessel is located in the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3 based on whether a center of gravity, a geometric center of the vessel, or another location of the vessel is located in the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3.

If in step S12-4 the controller 33 determines that the vessel is located in the first starboard side docking lane SDL1, the process proceeds to step S12-8. If in step S12-4 the controller 33 determines that the vessel is located in the second starboard side docking lane SDL2, the process proceeds to step S12-9. If in step S12-4 the controller 33 determines that the vessel is located in the third starboard side docking lane SDL3, the process proceeds to step S12-10.

In an example embodiment discussed above, step S12-2, step S12-3, and step S12-4 are performed separately. However, this is non-limiting, and steps S12-2 and S12-3, or steps S12-2 and S12-4, can be performed simultaneously based on a location of a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel. For example, the controller 33 can be configured or programmed to directly determine in which of the first portside docking lane PDL1, the second portside docking lane PDL2, the third portside docking lane PDL3, the first starboard side docking lane SDL1, the second starboard side docking lane SDL2, or the third starboard side docking lane SDL3 the vessel is located.

Next, steps S12-5 through S12-10 will be discussed in detail with respect to FIG. 12.

In step S12-5, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a first forward-starboard side movement control, as shown in FIG. 9C, for example. In order to perform the first forward-starboard side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b according to a first ratio that results in the net force F3 acting on the vessel at a first angle A1θ with respect to the center line C1 of the vessel.

In step S12-5, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1. For example, while the vessel may enter the first starboard side docking lane SDL1 as a result of the first forward-starboard side movement control being performed, the vessel may also enter the second portside docking lane PDL2 due to current and/or wind acting on the vessel in a portside direction.

In step S12-5, if the controller 33 determines that the vessel enters the second portside docking lane PDL2 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), then the process proceeds to step S12-6. On the other hand, if in step S12-5 the controller 33 determines that the vessel enters the first starboard side docking lane SDL1, then the process proceeds to step S12-8.

In step S12-6, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a second forward-starboard side movement control, as shown in FIG. 9D, for example. In order to perform the second forward-starboard side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a forward moving state and the propulsion device 3b to a rearward moving state, and sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be greater than the magnitude of the propulsion device 3b according to a second ratio that results in the net force F3 acting on the vessel at a second angle A2θ with respect to the center line C1 of the vessel.

In an example embodiment, the second angle A2θ of the second forward-starboard side movement control (e.g., as shown in FIG. 9D) is greater than the first angle A1θ of the first forward-starboard side movement control (e.g., as shown in FIG. 9C). In other words, the net force F3 acting on the vessel in the second forward-starboard side movement control is directed in a more lateral starboard direction than the net force F3 acting on the vessel in the first forward-starboard side movement control.

In an example embodiment, the controller 33 can set the magnitudes of the propulsion device 3a and the propulsion device 3b such that the net force F3 acting on the vessel in the second forward-starboard side movement control has a greater magnitude than the net force F3 acting on the vessel in the first forward-starboard side movement control.

In step S12-6, the controller 33 also monitors the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1. For example, while the vessel may enter the first portside docking lane PDL1 (e.g., as a result of the second forward-starboard side movement control being performed), the vessel may also enter the third portside docking lane PDL3 due to current and/or wind acting on the vessel in a portside direction.

In step S12-6, if the controller 33 determines that the vessel enters the third portside docking lane PDL3 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), then the process proceeds to step S12-7. On the other hand, if in step S12-6 the controller 33 determines that the vessel enters the first portside docking lane PDL1, then the process proceeds to step S12-5.

In step S12-7, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the starboard transverse movement control (see FIG. 5A). As discussed above with respect to FIG. 5A, in order to perform the starboard transverse movement control, the controller 33 sets the left propulsion device 3a to the forward moving state and sets the right propulsion device 3b to the rearward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the right direction and the vessel 1 is moved in the right direction. In an example embodiment, the controller 33 can be configured or programmed to set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, based on a lateral distance from the transit line TL. For example, the controller 33 can set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, to increase when a distance between the vessel and the transit line increases and decrease when the distance between the vessel and the transit line decreases. In this way, if the vessel continues to move away from the transit line TL when the vessel is located in the third portside docking lane PDL3 (e.g., as a result of current and/or wind acting on the vessel in a portside direction), the net force F3 oriented in the right direction can be increased to attempt to move the vessel back towards the transit line TL.

In step S12-7, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 as a result of the starboard transverse movement control being performed. In step S12-7, if the controller 33 determines that the vessel enters the second portside docking lane PDL2, then the process proceeds to step S12-6.

In step S12-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a first forward-port side movement control, as shown in FIG. 9A, for example. In order to perform the first forward-port side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b according to a first ratio that results in the net force F3 acting on the vessel at a first angle A1θ with respect to the center line C1 of the vessel.

In step S12-8, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1. For example, while the vessel may enter the first portside docking lane PDL1 (e.g., as a result of the first forward port side movement control being performed), the vessel may also enter the second starboard docking lane SDL2 due to current and/or wind acting on the vessel in a starboard side direction.

In step S12-8, if the controller 33 determines that the vessel enters the second starboard side docking lane SDL2 (e.g., as a result of current and/or wind acting on the vessel in a starboard side direction), then the process proceeds to step S12-9. On the other hand, if in step S12-8 the controller 33 determines that the vessel enters the first portside docking lane PDL1, then the process proceeds to step S12-5.

In step S12-9, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform a second forward-port side movement control, as shown in FIG. 9B, for example. In order to perform the second forward-port side movement control, the controller 33 sets the steering angle of the left propulsion device 3a and that of the right propulsion device 3b such that the left and right propulsion devices 3a and 3b are oriented opposite (e.g., bilaterally opposite) to each other such that each is slanted at a predetermined angle B1 with respect to the back-and-forth direction. Additionally, the controller 33 sets the propulsion device 3a to a rearward moving state and the propulsion device 3b to a forward moving state, and sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b. The net force F3 is a net force of the propulsive force F1 of the left propulsion device 3a and the propulsive force F2 of the right propulsion device 3b, and the predetermined angle B1 is set such that a line of action of the net force F3 passes through a center of gravity G1 of the vessel 1. In an example embodiment, the controller 33 sets the magnitude of the propulsion device 3a to be less than the magnitude of the propulsion device 3b according to a second ratio that results in the net force F3 acting on the vessel at a second angle A2θ with respect to the center line C1 of the vessel.

In an example embodiment, the second angle A2θ of the second forward-port side movement control (e.g., as shown in FIG. 9B) is greater than the first angle A1θ of the first forward-port side movement control (e.g., as shown in FIG. 9A). In other words, the net force F3 acting on the vessel in the second forward-port side movement control is directed in a more lateral portside direction than the net force F3 acting on the vessel in the first forward-port side movement control.

In an example embodiment, the controller 33 can set the magnitudes of the propulsion device 3a and the propulsion device 3b such that the net force F3 acting on the vessel in the second forward-port side movement control has a greater magnitude than the net force F3 acting on the vessel in the first forward-port side movement control.

In step S12-9, the controller 33 also monitors the location of the vessel to determine if the vessel enters the third starboard side docking lane SDL3 or the first starboard side docking lane SDL1. For example, while the vessel may enter the first starboard side docking lane SDL1 as a result of the second forward-port side movement control being performed, the vessel may also enter the third starboard side docking lane SDL3 due to current and/or wind acting on the vessel in a starboard side direction.

In step S12-9, if the controller 33 determines that the vessel enters the third starboard side docking lane SDL3 (e.g., as a result of current and/or wind acting on the vessel in a starboard side direction), then the process proceeds to step S12-10. On the other hand, if in step S12-9 the controller 33 determines that the vessel enters the first starboard side docking lane SDL1, then the process proceeds to step S12-8.

In step S12-10, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the portside transverse movement control (see FIG. 5B). As discussed above with respect to FIG. 5B, in order to perform the portside transverse movement control, the controller 33 sets the left propulsion device 3a to the rearward moving state and sets the right propulsion device 3b to the forward moving state. Additionally, the controller 33 sets the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b to be equal. Accordingly, the net force F3 is oriented in the left direction and the vessel 1 is moved in the left direction. In an example embodiment, the controller 33 can be configured or programmed to set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, based on a lateral distance from the transit line TL. For example, the controller 33 can set the magnitude of the propulsive force F1 of the left propulsion device 3a and that of the propulsive force F2 of the right propulsion device 3b, which are equal, to increase when a distance between the vessel and the transit line increases, and to decrease when the distance between the vessel and the transit line decreases. In this way, if the vessel continues to move away from the transit line TL when the vessel is located in the third starboard docking lane SDL3 (e.g., as a result of current and/or wind acting on the vessel in a starboard direction), the net force F3 oriented in the left direction can be increased to attempt to move the vessel back towards the transit line TL.

In step S12-10, the controller 33 also monitors the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 as a result of the portside transverse movement control being performed. In step S12-10, if the controller 33 determines that the vessel enters the second starboard side docking lane PDL3, then the process proceeds to step S12-9.

In an example embodiment of the present invention, the controller 33 can be configured or programmed to control the propulsion devices 3a and 3b such that the magnitude of the net force F3 generated in each of the first forward-starboard side movement control in step S12-5, the second forward-starboard side movement control in step S12-6, the starboard transverse movement control in step S12-7, the first forward-port side movement control in step S12-8, the second forward-port side movement control in step S12-9, and the portside transverse movement control in step S12-10 are generated/set based on an input(s) from a user/vessel operator. For example, the user/vessel operator can set magnitude/force value(s) for the net force F3 to be generated in each of the first forward-starboard side movement control in step S12-5, the second forward-starboard side movement control in step S12-6, the starboard transverse movement control in step S12-7, the first forward-port side movement control in step S12-8, the second forward-port side movement control in step S12-9, and the portside transverse movement control in step S12-10 before the forward zigzag moving mode is executed, and these value(s) can be saved in the memory 37 of the controller 33. In this way, the controller 33 is configured or programmed to set a magnitude of the net force F3 based on a user input.

In an example embodiment of the present invention, the controller 33 can be configured or programmed to control the propulsion devices 3a and 3b such that the magnitude of the net force F3 generated in each of the first forward-starboard side movement control in step S12-5, the second forward-starboard side movement control in step S12-6, the starboard transverse movement control in step S12-7, the first forward-port side movement control in step S12-8, the second forward-port side movement control in step S12-9, and the portside transverse movement control in step S12-10 are generated/set based on a disturbance value(s) (e.g., a wind force value and/or a current force value) detected by the disturbance sensor 39. For example, the magnitude of the net force F3 to be generated in each of the first forward-starboard side movement control in step S12-5, the second forward -starboard side movement control in step S12-6, the starboard transverse movement control in step S12-7, the first forward-port side movement control in step S12-8, the second forward-port side movement control in step S12-9, and the portside transverse movement control in step S12-10 can be multiplied by a disturbance factor (e.g., 1.1, 1.5, or 2, for example) when the disturbance value detected by the disturbance sensor 39 is greater than or equal to a disturbance value threshold. In this way, the controller 33 is configured or programmed to set a magnitude of the net force F3 based on a disturbance value detected by the disturbance sensor 39.

An example of the forward zigzag moving mode will now be discussed with respect to FIGS. 10B and 12. In step S12-1, the controller 33 sets the transit line TL, which is a line that connects the starting point SP of the vessel and the desired ending point EP of the vessel.

As discussed above, the controller 33 can be configured or programmed to determine a location of the vessel based on a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel. The controller 33 can be configured or programmed to determine the location of vessel at a predetermined interval of time (e.g., every 0.1 seconds or every 0.5 seconds) during steps S12-2 through S12-10 of the forward zigzag moving mode.

In step S12-2, the controller 33 determines that the vessel is located on the starboard side of the transit line TL at time t0, and the process proceeds to step S12-4. In step S11-4, the controller 33 determines that the vessel is located in the first starboard side docking lane SDL1 at time t0, and the process proceeds to step S12-8. In step S12-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-port side movement control (FIG. 9A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t1, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S12-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-starboard side movement control (FIG. 9C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t2, the controller 33 determines that the vessel has entered the second portside docking lane PDL2 (e.g., due to current and/or wind acting on the vessel in a portside direction). As a result, at time t2, the process proceeds to step S12-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-starboard side movement control (FIG. 9D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t3, the controller 33 determines that the vessel remains in the second portside docking lane PDL2. As a result, at time t3, the process remains at step S12-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-starboard side movement control (FIG. 9D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t4, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S12-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-starboard side movement control (FIG. 9C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t5, the controller 33 determines that the vessel has entered the first starboard side docking lane SDL1, and the process proceeds to step S12-8. In step S12-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-port side movement control (FIG. 9A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t6, the controller 33 determines that the vessel has entered the second starboard side docking lane SDL2 (e.g., due to current and/or wind acting on the vessel in a starboard side direction). As a result, at time t6, the process proceeds to step S12-9 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-port side movement control (FIG. 9B), and monitor the location of the vessel to determine if the vessel enters the third starboard docking lane SDL3 or the first starboard docking lane SDL1.

At time t7, the controller 33 determines that the vessel has entered the third starboard docking lane SDL3 (e.g., due to a strong current and/or wind acting on the vessel in a starboard side direction). As a result, at time t7, the process proceeds to step S12-10 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the portside transverse movement control (see FIG. 5B), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 as a result of the portside transverse movement control being performed.

At time t8, the controller 33 determines that the vessel has entered the second starboard side docking lane SDL2. As a result, at time t8, the process proceeds to step S12-9 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-port side movement control (FIG. 9B), and monitor the location of the vessel to determine if the vessel enters the third starboard docking lane SDL3 or the first starboard docking lane SDL1.

At time t9, the controller 33 determines that the vessel has entered the first starboard side docking lane SDL1, and the process proceeds to step S12-8. In step S12-8, the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-port side movement control (FIG. 9A), and monitor the location of the vessel to determine if the vessel enters the second starboard side docking lane SDL2 or the first portside side docking lane PDL1.

At time t10, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S12-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-starboard side movement control (FIG. 9C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t11, the controller 33 determines that the vessel has entered the second portside docking lane PDL2 (e.g., due to current and/or wind acting on the vessel in a portside direction). As a result, at time t11, the process proceeds to step S12-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-starboard side movement control (FIG. 9D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At times t12 and t13, the controller 33 determines that the vessel remains in the second portside docking lane PDL2. As a result, at times t12 and t13, the process remains at step S11-6 in which the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the second forward-starboard side movement control (FIG. 9D), and monitor the location of the vessel to determine if the vessel enters the third portside docking lane PDL3 or the first portside docking lane PDL1.

At time t14, the controller 33 determines that the vessel has entered the first portside side docking lane PDL1. As a result, the process proceeds to step S12-5, and the controller 33 is configured or programmed to control the propulsion devices 3a and 3b and the steering actuators 26a and 26b to cause the vessel 1 to perform the first forward-starboard side movement control (FIG. 9C), and monitor the location of the vessel to determine if the vessel enters the second portside docking lane PDL2 or the first starboard side docking lane SDL1.

At time t15, the controller 33 determines that the vessel has reached the ending point EP and the process ends.

In example embodiments of the forward zigzag mode, the first portside docking lane PDL1 and the first starboard side docking lane SDL1 can be located immediately adjacent to the transit line TL. However, this is non-limiting, and the first portside docking lane PDL1 can each be spaced away from transit line TL by a first predetermined distance, and the first starboard side docking lane SDL1 each be spaced away from transit line TL by a second predetermined distance the same as or different from the first predetermined distance. The first portside docking lane PDL1 being spaced away from transit line TL by the first predetermined distance, and the first starboard side docking lane SDL1 being spaced away from transit line TL by the second predetermined, can create a “deadband” surrounding the transit line TL, which can prevent the forward zigzag mode from transitioning between the first forward-port side movement control (FIG. 9A) and the first forward-starboard side movement control (FIG. 9C) at a rate that negatively affects the functionality of the forward zigzag mode, particularly when the vessel is operating in conditions with no wind or current or substantially no wind or current. For example, the clutch 21 of each of the propulsion devices 3a and 3b can be moved to the neutral position when the vessel is located in the “deadband” surrounding the transit line TL.

In an example embodiment of the present invention, when the vessel has crossed the transit line L from the first starboard side docking lane SDL1 to the first portside docking lane PDL1, the controller 33 can be configured or programmed to wait to switch from the first forward-port side movement control (FIG. 9A) to the first forward-starboard side movement control (FIG. 9C) until the vessel is a predetermined distance from the transit line TL (when located in the first portside docking lane PDL1). In other words, when the vessel has crossed the transit line L from the first starboard side docking lane SDL1 to the first portside docking lane PDL1, the first starboard side docking lane SDL1 can be modified such that a portion of the first starboard side docking lane SDL1 crosses over to a portside of the transit line TL by a predetermined distance.

Similarly, when the vessel has crossed the transit line L from the first portside docking lane PDL1 to the first starboard side docking lane SDL1, the controller 33 can be configured or programmed to wait to switch from the first forward-starboard side movement control (FIG. 9C) to the first forward-port side movement control (FIG. 9A) until the vessel is a predetermined distance from the transit line TL (when located in the first starboard side docking lane SDL1). In other words, when the vessel has crossed the transit line L from the first portside docking lane PDL1 to the first starboard side docking lane SDL1, the first portside docking lane PDL1 can be modified such that a portion of the first portside docking lane PDL1 crosses over to a starboard side of the transit line TL by a predetermined distance.

This functionality can prevent the forward zigzag mode from transitioning between the first forward-port side movement control (FIG. 9A) and the first forward-starboard side movement control (FIG. 9C) at a rate that negatively affects the functionality of the forward zigzag mode, particularly when the vessel is operating in conditions with no wind or current or substantially no wind or current.

As discussed above, a vessel according to an example embodiment can include a left propulsion device 3a and a right propulsion device 3b. However, this is non-limiting, and the vessel can include three or more propulsion devices and the forward zigzag moving mode and the rearward zigzag mode can be performed using a vessel that includes three or more propulsion devices. Additionally, the propulsion devices are not limited to outboard motors, and may be another type of propulsion device such as inboard-outboard motors or jet thrusters. The configuration of each propulsion device is not limited to that in the above-described example embodiments, and may be changed.

In example embodiments discussed above, the forward zigzag moving mode and the rearward zigzag mode use a first portside docking lane PDL1, the second portside docking lane PDL2, the third portside docking lane PDL3, a first starboard side docking lane SDL1, a second starboard side docking lane SDL2, or a third starboard side docking lane SDL3. However, this is non-limiting, and the forward zigzag moving mode and the rearward zigzag mode can use any number of portside and starboard side docking lanes. Correspondingly, the rearward zigzag mode can use any number of rearward-port side movement controls and rearward-starboard side movement controls, and the forward zigzag mode can use any number of forward-port side movement controls and forward-starboard side movement controls. In other words, the rearward zigzag mode can use an unlimited number of rearward-port side movement controls and rearward-starboard side movement controls based on a vessel distance from the transit line TL, and the forward zigzag mode can use an unlimited number of forward-port side movement controls and forward-starboard side movement controls based on a vessel distance from the transit line TL. For example, the rearward zigzag mode can use an unlimited number of rearward-port side movement controls and rearward-starboard side movement controls wherein the angle with respect to the center line C1 of the vessel increases as a vessel distance from the transit line TL (w) increases, and the forward zigzag mode can use an infinite number of forward-port side movement controls and forward-starboard side movement controls wherein the angle with respect to the center line C1 of the vessel increases as a vessel distance from the transit line TL (w) increases.

In an example embodiment, a portion or an entirety of each of the controller 33 and the processor 36 and/or the functional units or blocks thereof as described herein (e.g., in FIGS. 11 and 12) with respect to the various example embodiments of the present invention can be implemented in one or more circuits or circuitry, such as an integrated circuit(s) or as an LSI (large scale integration). For example, the controller 33 and the processor 36 can include one or more circuits or circuitry such as a microprocessor, a microcontroller, a multi-core processor, a central processing unit (CPU), a graphics processing unit (GPU), and a superscalar processor, for example, in forms such as semiconductor integrated circuit chip packages, semiconductor integrated circuit modules, and single-board computers that can operate in connection with built-in or external memory. Each functional unit or block of each of the controller 33 and the processor 36 may be individually made into an integrated circuit chip. Alternatively, a portion or an entirety of the functional units or blocks of each of the controller 33 and the processor 36 may be integrated and made into an integrated circuit chip. Additionally, the method of forming a circuit or circuitry defining each of the controller 33 and the processor 36 is not limited to LSI, and an integrated circuit may be implemented by a dedicated circuit or one or more general-purpose processors or controllers that are specifically programed to define a special-purpose processor or controller to perform one or more of the functions, operations, steps, or processes disclosed herein. Further, if a technology or technologies for forming an integrated circuit, which replaces LSI, arises as a result of advances in semiconductor technology, an integrated circuit formed by that technology may be used. In an example embodiment, the controller 33 and the processor 36 and the various possible corresponding structures disclosed herein provide non-limiting examples that correspond to the “controller” recited in the claims of this patent application.

Furthermore, a program which is operated in each of the controller 33 and the processor 36 and/or other elements of various example embodiments of the present invention, is a program (e.g., a program causing a computer to perform a function or functions, operations, steps, or processes) controlling a controller, in order to realize one or more functions, operations, steps, or processes of the various example embodiments according to the present invention, including each of the various circuits or circuitry described herein and recited in the claims. Further, information which is handled by the controller may be temporarily accumulated in a RAM at the time of the processing. Thereafter, the information is stored in various types of circuitry in the form of ROMs and HDDs, and is read out by circuitry within, or included in combination with, the controller 33 and the processor 36 as necessary, and modification or write-in may be performed thereto. Examples of a recording medium storing the program or programs can include integrated circuits on a same semiconductor chip that makes up the controller 33 and the processor 36, integrated circuits formed on a different semiconductor chip from the controller 33 and the processor 36, or various storage media that can communicate data and address signals via a network bus. As a recording medium storing the program or programs, any one of, or a combination of, a semiconductor medium (for example, the ROM, a nonvolatile memory card or the like), an optical recording medium (for example, a DVD, an MO, an MD, a CD, a BD or the like), and a magnetic recording medium (for example, a magnetic tape, a flexible disc or the like) may be used. Moreover, by executing the loaded program, the functions, operations, steps, or processes of the various example embodiments of the present invention are not only realized, but the functions, operations, steps, or processes of example embodiments of the present invention may be realized by processing the loaded program in combination with an operating system or other application programs, based on an instruction of the program.

Moreover, in a case of being distributed in a market, the program or programs can be distributed by being stored in a portable recording medium, or the program or programs can be transmitted to a server computer which is connected through a network such as the Internet. In this case, a storage device of the general purpose or special purpose computer is also included in example embodiments of the present invention. In addition, in the example embodiments described above, a portion or an entirety of the various functional units or blocks may be realized as an LSI which is typically an integrated circuit. Each functional unit or block of the controller 33 may be individually chipped, or a portion thereof, or the whole thereof may be chipped by being integrated. In a case of making each functional block or unit as an integrated circuit, an integrated circuit controller that controls the integrated circuits, may be added.

Additionally, the method for making an integrated circuit is not limited to the LSI, and may be realized by a single-purpose circuit or a general-purpose processor that is programmable to perform the functions described above to define a special-purpose computer. Moreover, in a case of an appearance of a technology for making an integrated circuit which replaces the LSI due to an advance of a semiconductor technology, it is possible to use an integrated circuit depending on the technology.

Finally, it should be noted that the description and recitation in the claims of this patent application referring to “CPU”, “control unit”, “computer”, “processor”, “microprocessor”, “controller”, “circuit”, or “circuitry” is in no way limited to an implementation that is hardware only, and as persons of ordinary skill in the relevant art would know and understand, such descriptions and recitations of “CPU”, “control unit”, “computer”, “processor”, “microprocessor”, “controller”, “circuit”, or “circuitry” include combined hardware and software implementations in which the controller, circuit, or circuitry is operative to perform functions and operations based on machine readable programs, software or other instructions in any form that are usable to operate the controller, circuit, or circuitry.

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 system for steering a vessel, the system comprising:

a plurality of propulsion devices including a first propulsion device and a second propulsion device;

a first actuator connected to the first propulsion device to change a steering angle of the first propulsion device;

a second actuator connected to the second propulsion device to change a steering angle of the second propulsion device; and

a controller configured or programmed to alternate between a port side movement control and a starboard side movement control.

2. The system for steering the vessel according to claim 1, wherein

when the port side movement control is performed, the controller is configured or programmed to: set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are each oriented slanted with respect to a back-and-forth direction of the vessel; and control a propulsive force of the first propulsion device and a propulsive force of the second propulsion device such that a net force of the propulsive forces of the first and second propulsion devices is oriented in a port side direction; and

when the starboard side movement control is performed, the controller is configured or programmed to: set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are each oriented slanted with respect to the back-and-forth direction of the vessel; and control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a starboard side direction.

3. The system for steering the vessel according to claim 2, wherein

the controller is configured or programmed to alternate between the port side movement control and the starboard side movement control between a start pointing and an end pointing of a transit line;

the controller is configured or programmed to determine whether the vessel is located on a port side or a starboard side of the transit line;

when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to perform the starboard side movement control; and

when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to perform the port side movement control.

4. The system for steering the vessel according to claim 3, wherein

when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a first port side docking lane or a second port side docking lane;

the first port side docking lane and the second port side docking lane are each virtual docking lanes on the port side of the transit line;

the first port side docking lane is located closer to the transit line than the second port side docking lane in a lateral direction perpendicular to the transit line;

when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a first starboard side docking lane or a second starboard side docking lane;

the first starboard side docking lane and the second starboard side docking lane are each virtual docking lanes on the starboard side of the transit line; and

the first starboard side docking lane is located closer to the transit line than the second starboard side docking lane in the lateral direction perpendicular to the transit line.

5. The system for steering the vessel according to claim 4, wherein

when the controller determines that the vessel is located in the first port side docking lane, the controller is configured or programmed to perform a first starboard side movement control in which the net force acting on the vessel is at a first angle with respect to a center line of the vessel;

when the controller determines that the vessel is located in the second port side docking lane, the controller is configured or programmed to perform a second starboard side movement control in which the net force acting on the vessel is at a second angle with respect to the center line of the vessel, the second angle being greater than the first angle;

when the controller determines that the vessel is located in the first starboard side docking lane, the controller is configured or programmed to perform a first port side movement control in which the net force acting on the vessel is at a third angle with respect to the center line of the vessel; and

when the controller determines that the vessel is located in the second starboard side docking lane, the controller is configured or programmed to perform a second port side movement control in which the net force acting on the vessel is at a fourth angle with respect to the center line of the vessel, the fourth angle being greater than the third angle.

6. The system for steering the vessel according to claim 5, wherein

the controller is configured or programmed to set a magnitude of the net force of the second starboard side movement control to be larger than a magnitude of the net force of the first starboard side movement control; and

the controller is configured or programmed to set a magnitude of the net force of the second port side movement control to be larger than a magnitude of the net force of the first port side movement control.

7. The system for steering the vessel according to claim 4, wherein

each of the first port side docking lane, the second port side docking lane, the first starboard side docking lane, and the second starboard side docking lane is less than 0.5 times a width of the vessel.

8. The system for steering the vessel according to claim 3, wherein

the port side movement control is a port side transverse movement control in which the net force is perpendicular to the transit line; and

the starboard side movement control is a starboard side transverse movement control in which the net force is perpendicular to the transit line.

9. The system for steering the vessel according to claim 3, wherein

the controller is configured or programmed to set a magnitude of the net force of the starboard side movement control based on a distance of the vessel from the transit line; and

the controller is configured or programmed to set a magnitude of the net force of the port side movement control based on a distance of the vessel from the transit line.

10. The system for steering the vessel according to claim 3, wherein

the controller is configured or programmed to determine whether the vessel is located on the port side or the starboard side of the transit line based on a location of the vessel including a center of gravity of the vessel, a geometric center of the vessel, or another location of the vessel.

11. The system for steering the vessel according to claim 3, wherein

the controller is configured or programmed to determine whether the vessel is located on the port side or the starboard side of the transit line at a predetermined interval of time.

12. The system for steering the vessel according to claim 3, wherein

when the controller determines that the vessel is located on the port side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a port side docking lane which is a virtual docking lane on the port side of the transit line;

the port side docking lane is spaced away from the transit line by a first predetermined distance;

when the controller determines that the vessel is located on the starboard side of the transit line, the controller is configured or programmed to determine whether the vessel is located in a starboard side docking lane which is a virtual docking lane on the starboard side of the transit line; and

the starboard side docking lane is spaced away from the transit line by a second predetermined distance that is the same as or different from the first predetermined distance.

13. The system for steering the vessel according to claim 3, wherein

when the controller determines that the vessel is located on the port side of the transit line after having crossed the transit line, the controller is configured or programmed to perform the starboard side movement control when the vessel is a predetermined distance from the transit line; and

when the controller determines that the vessel is located on the starboard side of the transit line after having crossed the transit line, the controller is configured or programmed to perform the port side movement control when the vessel is a predetermined distance from the transit line.

14. The system for steering the vessel according to claim 3, wherein the starting point and the ending point are determined based on map data or sensor data.

15. The system for steering the vessel according to claim 2, wherein

when the port side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a rearward port side direction; and

when the starboard side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a rearward starboard side direction.

16. The system for steering the vessel according to claim 2, wherein

when the port side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a forward port side direction; and

when the starboard side movement control is performed, the controller is configured or programmed to control the propulsive force of the first propulsion device and the propulsive force of the second propulsion device such that the net force of the propulsive forces of the first and second propulsion devices is oriented in a forward starboard side direction.

17. The system for steering the vessel according to claim 2, wherein

when the port side movement control is performed, a line of action of the net force of the propulsive forces of the first and second propulsion devices extends through a center of gravity of the vessel; and

when the starboard side movement control is performed, a line of action of the net force of the propulsive forces of the first and second propulsion devices extends through the center of gravity of the vessel.

18. The system for steering the vessel according to claim 2, wherein

when the port side movement control is performed, the controller is configured or programmed to set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are oriented opposite to each other; and

when the starboard side movement control is performed, the controller is configured or programmed to set the steering angles of the first and second propulsion devices such that the first and second propulsion devices are oriented opposite to each other.

19. The system for steering the vessel according to claim 2, wherein

the controller is configured or programmed to set a magnitude of the net force based on a user input and/or a disturbance value detected by a disturbance sensor.

20. The system for steering the vessel according to claim 4, wherein

when the controller determines that the vessel is located in the first portside docking lane, the controller is configured or programmed to perform a first starboard movement control in which the net force is set to a first net force;

when the controller determines that the vessel is located in the second portside docking lane, the controller is configured or programmed to perform a second starboard movement control in which the net force is set to a second net force that is larger in magnitude than the first net force;

when the controller determines that the vessel is located in the first starboard side docking lane, the controller is configured or programmed to perform a first portside movement control in which the net force is set to a third net force; and

when the controller determines that the vessel is located in the second starboard side docking lane, the controller is configured or programmed to perform a second portside movement control in which the net force is set to a fourth net force that is larger in magnitude than the third net force.

21. The system for steering the vessel according to claim 4, wherein

the controller is configured or programmed to set a width of each of the first portside docking lane, the second portside docking lane, the first starboard side docking lane, and the second starboard side docking lane based on a user input and/or a disturbance value detected by a disturbance sensor.

22. The system for steering the vessel according to claim 1, wherein

the first propulsion device includes a first outboard motor; and

the second propulsion device includes a second outboard motor.

23. A method executed by a controller to steer a vessel including a first propulsion device and a second propulsion device, the method comprising:

alternatingly performing a port side movement control and a starboard side movement control between a start pointing and an end pointing of a transit line of the vessel.