Course control system for marine vessel, and marine vessel

1. A course control system for a marine vessel having a propeller that provides propulsive force to the marine vessel, the course control system comprising:

a course changing mechanism that changes a course of the marine vessel; and

a controller configured or programmed to:

detect a sudden movement of the marine vessel originating from broaching caused by a following wave of the marine vessel in a case where

an actual yaw rate at a time when the marine vessel turns its head is greater than a yaw rate estimated from an amount of operation by a vessel operator, and

the marine vessel changed its course in a direction in which the marine vessel is to encounter the following wave, and

upon detecting the sudden movement of the marine vessel originating from the broaching, control a rotation rate of the propeller and/or cause the course changing mechanism to change the course of the marine vessel.

2. The course control system according to claim 1 , wherein, upon detecting the sudden movement of the marine vessel originating from the broaching after detecting the broaching, the controller causes the course changing mechanism to change the course of the marine vessel.

3. The course control system according to claim 2 , wherein the controller causes the course changing mechanism to change the course of the marine vessel, to thereby reduce a difference between a moving direction of the marine vessel and a traveling direction of the following wave.

4. The course control system according to claim 1 , wherein when a crosswise movement component of the marine vessel becomes greater than a predetermined value after the controller detects the sudden movement of the marine vessel originating from the broaching, the controller increases the rotation rate of the propeller.

5. The course control system according to claim 1 , wherein the controller

judges that the marine vessel has recovered from the sudden movement originating from the broaching, responsive to the course of the marine vessel returning to a course the marine vessel was taking before occurrence of the sudden movement after the controller causes the course changing mechanism to change the course of the marine vessel upon detecting the sudden movement, and

upon judging that the marine vessel has recovered from the sudden movement, causes the course changing mechanism to stop changing the course of the marine vessel.

6. The course control system according to claim 1 , wherein

the marine vessel further includes at least one posture control tab for controlling a posture of the marine vessel, and at least one actuator that respectively actuates the at least one posture control tab, and

when preconditions of occurrence of the broaching are satisfied, the controller causes the at least one actuator to retract the at least one posture control tab into a hull of the marine vessel.

7. The course control system according to claim 1 , wherein the controller judges that preconditions of occurrence of the broaching are satisfied in a case where

a wavelength of the following wave is 0.6 to 2.3 times as long as a length between perpendiculars of the marine vessel, and

a condition that a wave height of the following wave is equal to or greater than 0.04 times as long as the length between the perpendiculars is satisfied.

8. The course control system according to claim 7 , wherein the wavelength of the following wave is obtained based on a ship speed, an acceleration, and a moving direction of the marine vessel and the traveling direction of the following wave.

9. A marine vessel comprising:

a propeller that provides propulsive force to the marine vessel; and

a course control system including:

a course changing mechanism that changes a course of the marine vessel; and

a controller configured or programmed to:

detect a sudden movement of the marine vessel originating from broaching caused by a following wave of the marine vessel in a case where

an actual yaw rate at a time when the marine vessel turns its head is greater than a yaw rate estimated from an amount of operation by a vessel operator, and

the marine vessel changed its course in a direction in which the marine vessel is to encounter the following wave, and

upon detecting the sudden movement of the marine vessel originating from the broaching, control a rotation rate of the propeller and/or cause the course changing mechanism to change the course of the marine vessel.

10. The marine vessel according to claim 9 , wherein, upon detecting the sudden movement of the marine vessel originating from the broaching after detecting the broaching, the controller causes the course changing mechanism to change the course of the marine vessel.

11. The marine vessel according to claim 10 , wherein the controller causes the course changing mechanism to change the course of the marine vessel, to thereby reduce a difference between a moving direction of the marine vessel and a traveling direction of the following wave.

12. The marine vessel according to claim 9 , wherein when a crosswise movement component of the marine vessel becomes greater than a predetermined value after the controller detects the sudden movement of the marine vessel originating from the broaching, the controller increases the rotation rate of the propeller.

13. The marine vessel according to claim 9 , wherein the controller

judges that the marine vessel has recovered from the sudden movement originating from the broaching, responsive to the course of the marine vessel returning to a course the marine vessel was taking before occurrence of the sudden movement after the controller causes the course changing mechanism to change the course of the marine vessel upon detecting the sudden movement, and

upon judging that the marine vessel has recovered from the sudden movement, causes the course changing mechanism to stop changing the course of the marine vessel.

14. The marine vessel according to claim 9 , further comprising

at least one posture control tab for controlling a posture of the marine vessel; and

at least one actuator that respectively actuates the at least one respective posture control tab,

wherein, when preconditions of occurrence of the broaching are satisfied, the controller causes the at least one actuator to retract the at least one posture control tab into a hull of the marine vessel.

15. The marine vessel according to claim 9 , wherein the controller judges that preconditions of occurrence of the broaching are satisfied in a case where

a wavelength of the following wave is 0.6 to 2.3 times as long as a length between perpendiculars of the marine vessel, and

a condition that a wave height of the following wave is equal to or greater than 0.04 times as long as the length between the perpendiculars is satisfied.

16. The marine vessel according to claim 15 , wherein the wavelength of the following wave is obtained based on a ship speed, an acceleration, and a moving direction of the marine vessel and the traveling direction of the following wave.

17. A course control system for a marine vessel, comprising:

a controller configured or programmed to:

judges that preconditions of occurrence of a broaching are satisfied in a case where

a wavelength of a following wave is 0.6 to 2.3 times as long as a length between perpendiculars of the marine vessel, and

a condition that a wave height of the following wave is equal to or greater than 0.04 times as long as the length between the perpendiculars is satisfied.

18. The marine vessel of claim 9 , wherein the controller detects occurrence of broaching when a ship speed of the marine vessel is higher than a broaching occurrence critical speed.

19. The course control system of claim 1 , wherein the controller detects occurrence of broaching when a ship speed of the marine vessel is higher than a broaching occurrence critical speed.