# US 2019/0377347 A1 · Steering for marine propulsion unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0377347 A1 - Document ID: US20190377347A1 - Status: Published application - Kind: A1 - Application number: 16/430,471 - Filed: 2019-06-04 - Published: 2019-12-12 - Earliest claimed: 2018-06-08 - Assignees: Yamaha Hatsudoki Kabushiki Kaisha; Marine Canada Acquisition Inc. - Applicants: Yamaha Hatsudoki Kabushiki Kaisha; Marine Canada Acquisition Inc. - Inventors: Makoto MIZUTANI - Web page: https://patentgrep.com/patent/US20190377347A1 ## CPC - B63H 25/24: by electrical means - G05D 1/0206: {specially adapted to water vehicles} - B63H 20/12: Means enabling steering - B63H 25/42: Steering or dynamic anchoring by propulsive elements (by jets B63H25/46); Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers - F16H 25/20: Screw mechanisms (with automatic reversal F16H25/12) - F16H 2025/2043: {Screw mechanisms driving an oscillating lever, e.g. lever with perpendicular pivoting axis} - F16H 2025/2078: {the rotor being integrated with the nut or screw body} - 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 - F16H: GEARING ## Abstract A steering for a marine propulsion unit adjusts at least one of a required steering speed and a required steering torque such that the required steering speed and the required steering torque fall within an output region when the required steering speed and the required steering torque are outside the output region, sets a target steering angle according to the adjusted required steering speed and required steering torque, and sets the target steering angle according to a rotation angle of a steering wheel when the required steering speed and the required steering torque are within the output region. ## Claims ### Claim 1 A steering for a marine propulsion unit comprising: an electric actuator that changes a direction of a thrust force of the marine propulsion unit; a storage that stores an output region that is set based on a steering speed and a steering torque provided by the electric actuator; and a controller configured or programmed to: acquire a required steering speed and a required steering torque based on a rotation angle of a steering wheel; adjust at least one of the required steering speed and the required steering torque such that both the required steering speed and the required steering torque fall within the output region when both the required steering speed and the required steering torque are outside the output region; set a target steering angle based on at least one of the required steering speed and the required steering torque that has been adjusted; and set the target steering angle based on the rotation angle of the steering wheel when the required steering speed and the required steering torque are within the output region, and to drive and control the electric actuator according to the set target steering angle. ### Claim 2 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the controller is configured or programmed not to adjust the required steering torque but to adjust the required steering speed such that the required steering speed and the required steering torque fall within the output region. ### Claim 3 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the controller is configured or programmed to adjust both the required steering speed and the required steering torque when the required steering speed and the required steering torque do not fall within the output region even when the required steering speed is adjusted. ### Claim 4 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the storage stores a map showing the output region that is set based on the steering speed and the steering torque provided by the electric actuator. ### Claim 5 (depends on 4) The steering for a marine propulsion unit according to claim 4, wherein the storage stores a plurality of the maps showing a plurality of the output regions that are different from each other; and the controller is configured or programmed to select one of the plurality of maps according to an available current of the electric actuator. ### Claim 6 (depends on 5) The steering for a marine propulsion unit according to claim 5, wherein the plurality of maps include a normal map and a correction map in which the output region is corrected such that a maximum value of the steering torque according to the steering speed is smaller than that in the normal map; and the controller is configured or programmed to select the normal map when the available current of the electric actuator is not limited, and to select the correction map when the available current of the electric actuator is limited. ### Claim 7 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the controller is configured or programmed to update the output region based on an available current of the electric actuator. ### Claim 8 (depends on 7) The steering for a marine propulsion unit according to claim 7, wherein the controller is configured or programmed to limit the available current of the electric actuator and update the output region based on the limited available current when a temperature of the electric actuator is equal to or higher than a predetermined temperature. ### Claim 9 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the controller is configured or programmed to: update setting of the target steering angle at a predetermined time interval; and update the setting of the target steering angle according to the adjusted required steering speed and required steering torque in a state in which a degree of increase of the target steering angle at the predetermined time interval is reduced when the required steering speed and the required steering torque are outside the output region. ### Claim 10 (depends on 1) The steering for a marine propulsion unit according to claim 1, wherein the controller is configured or programmed to set the target steering angle such that a degree of increase of the target steering angle is proportional to a degree of change of the rotation angle of the steering wheel when the required steering speed and the required steering torque are within the output region.