US 11,987,341 B2
System for and method of controlling watercraft
Kento Sakurada, Shizuoka (JP)
Assigned to YAMAHA HATSUDOKI KABUSHIKI KAISHA, Shizuoka (JP)
Filed by YAMAHA HATSUDOKI KABUSHIKI KAISHA, Iwata (JP)
Filed on Jan. 7, 2022, as Appl. No. 17/570,417.
Claims priority of application No. 2021-028609 (JP), filed on Feb. 25, 2021.
Prior Publication US 2022/0266974 A1, Aug. 25, 2022
Int. Cl. B63H 25/42 (2006.01); B63B 79/10 (2020.01); B63B 79/40 (2020.01); B63H 25/06 (2006.01)
CPC B63H 25/42 (2013.01) [B63B 79/10 (2020.01); B63B 79/40 (2020.01); B63H 25/06 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A system for controlling a watercraft, the system comprising:
a marine propulsion device rotatable about a steering shaft;
a steering actuator to rotate the marine propulsion device about the steering shaft;
a position sensor to detect a present position of the watercraft;
a direction sensor to detect a present direction of the watercraft; and
a controller configured or programmed to:
control the marine propulsion device and the steering actuator such that the watercraft moves along a target course;
determine a target direction of the watercraft based on the target course;
calculate a directional difference between the target direction and the present direction;
determine a target yaw rate based on the directional difference with reference to target yaw rate data defining a relationship between the directional difference and the target yaw rate;
change a rudder angle of the marine propulsion device by controlling the steering actuator based on the target yaw rate;
determine which of rightward turning and leftward turning is being made by the watercraft;
impose a limitation on a leftward target yaw rate when the rightward turning is being made by the watercraft; and
impose a limitation on a rightward target yaw rate when the leftward turning is being made by the watercraft.