# US 10,766,589 B1 · System for and method of controlling watercraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,766,589 B1 - Document ID: US10766589B1 - Status: Granted - Kind: B1 - Application number: 16/219,988 - Filed: 2018-12-14 - Granted: 2020-09-08 - Earliest claimed: 2017-12-19 - Assignees: Yamaha Hatsudoki Kabushiki Kaisha - Applicants: Yamaha Hatsudoki Kabushiki Kaisha - Inventors: Makoto Ito - Web page: https://patentgrep.com/patent/US10766589B1 ## CPC - B63H 20/12: Means enabling steering - B63H 25/24: by electrical means - G05D 1/0206: {specially adapted to water vehicles} - B63H 2020/003: {Arrangements of two, or more outboard propulsion units} - B63H 2021/216: {using electric control means} - B63H 2025/026: {using multi-axis control levers, or the like, e.g. joysticks, wherein at least one degree of freedom is employed for steering, slowing down, or dynamic anchoring} - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES ## Abstract A controller receives a bow turning signal to turn a bow of a watercraft and a propulsion signal to move the watercraft forward or rearward. The controller controls left and right outboard motors under a first control when receiving the propulsion signal after receiving the bow turning signal in a composite in which the controller receives both the bow turning signal and the propulsion signal. The controller controls the left and right outboard motors and a steering actuator under a second control different from the first control when receiving the bow turning signal after receiving the propulsion signal in the composite operation. ## Claims ### Claim 1 A system for controlling a watercraft, the system comprising: a left outboard motor on a port side of the watercraft; a right outboard motor on a starboard side of the watercraft; a steering actuator that changes rudder angles of the right and left outboard motors; and a controller communicating with the right and left outboard motors and the steering actuator; wherein the controller receives a bow turning signal and a propulsion signal, the bow turning signal causing a bow of the watercraft to turn, the propulsion signal causing the watercraft to move forward or rearward; the controller controls the right and left outboard motors under a first control when receiving the propulsion signal after receiving the bow turning signal in a composite operation in which the controller receives both the bow turning signal and the propulsion signal; and the controller controls the right and left outboard motors and the steering actuator under a second control when receiving the bow turning signal after receiving the propulsion signal in the composite operation, the second control being different from the first control. ### Claim 2 (depends on 1) The system according to claim 1, wherein the controller controls the right and left outboard motors under the first control to cause a difference in direction and/or magnitude between thrusts generated by the right and left outboard motors; and the controller controls the steering actuator under the second control so as to change the rudder angles of the right and left outboard motors. ### Claim 3 (depends on 2) The system according to claim 2, wherein the controller changes each of the rudder angles of the right and left outboard motors in accordance with the bow turning signal under the second control. ### Claim 4 (depends on 2) The system according to claim 2, wherein the controller maintains each of the rudder angles of the right and left outboard motors constant under the first control. ### Claim 5 (depends on 2) The system according to claim 2, wherein the controller changes each of the thrusts generated by the right and left outboard motors in direction and/or magnitude in accordance with the propulsion signal under the first control. ### Claim 6 (depends on 2) The system according to claim 2, wherein the controller causes the thrusts generated by the right and left outboard motors to be the same in direction and magnitude under the second control. ### Claim 7 (depends on 1) The system according to claim 1, further comprising: a joystick that communicates with the controller; wherein the joystick outputs the bow turning signal in accordance with a twist operation of the joystick and outputs the propulsion signal in accordance with a tilt operation of the joystick. ### Claim 8 (depends on 7) The system according to claim 7, wherein the controller controls the right and left outboard motors and the steering actuator under the first control when the joystick is tilted forward or rearward while being twisted; and the controller controls the right and left outboard motors and the steering actuator under the second control when the joystick is twisted while being tilted forward or rearward. ### Claim 9 A method of controlling a watercraft, the watercraft including a left outboard motor, a right outboard motor, and a steering actuator, the left outboard motor being disposed on a port side of the watercraft, the right outboard motor being disposed on a starboard side of the watercraft, the steering actuator changing rudder angles of the right and left outboard motors, the method comprising: receiving a bow turning signal and a propulsion signal, the bow turning signal causing a bow of the watercraft to turn and the propulsion signal causing the watercraft to move forward or rearward; controlling the right and left outboard motors under a first control when the propulsion signal is received after the bow turning signal is received in a composite operation in which both the bow turning signal and the propulsion signal are received; and controlling the right and left outboard motors and the steering actuator under a second control different from the first control when the bow turning signal is received after the propulsion signal is received in the composite operation. ### Claim 10 (depends on 9) The method according to claim 9, wherein the first control includes controlling the right and left outboard motors to cause a difference in direction and/or magnitude between thrusts generated by the right and left outboard motors; and the second control includes controlling the steering actuator to change the rudder angles of the right and left outboard motors. ### Claim 11 (depends on 10) The method according to claim 10, wherein the second control includes changing each of the rudder angles of the right and left outboard motors in accordance with the bow turning signal. ### Claim 12 (depends on 10) The method according to claim 10, wherein the first control includes maintaining each of the rudder angles of the right and left outboard motors constant. ### Claim 13 (depends on 10) The method according to claim 10, wherein the first control includes changing each of the thrusts generated by the right and left outboard motors in direction and/or magnitude in accordance with the propulsion signal. ### Claim 14 (depends on 10) The method according to claim 10, wherein the second control includes causing the thrusts generated by the right and left outboard motors to be the same in direction and magnitude. ### Claim 15 (depends on 9) The method according to claim 9, wherein the watercraft further includes a joystick; the bow turning signal is outputted from the joystick in accordance with a twist operation of the joystick; and the propulsion signal is outputted from the joystick in accordance with a tilt operation of the joystick. ### Claim 16 (depends on 15) The method according to claim 15, wherein the first control includes controlling the right and left outboard motors and the steering actuator when the joystick is tilted forward or rearward while being twisted; and the second control controlling the right and left outboard motors and the steering actuator when the joystick is twisted while being tilted forward or rearward.