A ship steering device includes a handle which is mechanically separated from a rudder mechanism, a steering angle detecting unit that detects a steering angle of the handle, a rudder motor that drives the rudder mechanism, and a turn controller that controls, based on a steering characteristics map which associates a basic relation between the steering angle and a turn angle, the rudder motor so as to obtain the turn angle in accordance with the steering angle. The steering characteristics map has a characteristic such that, in a second steering region where the steering angle is larger than the steering angle in a first steering region, a change amount of the turn angle relative to the steering angle is large with respect to the first steering region where the steering angle is set from zero in advance.

An embodiment of a system for controlling a marine vessel includes an electrical power steering unit coupled to a mechanical control system, the mechanical control system including a steering wheel connected by a shaft to a mechanical cable assembly, the mechanical cable assembly configured to be actuated by the steering wheel to control a steering mechanism of the marine vessel. The electrical power steering unit includes an electric motor configured to apply a torque to the mechanical cable assembly. The system also includes a processor configured to control the electrical power steering unit to provide at least one of steering assist and control of the marine vessel.

An embodiment of a system for controlling a marine vessel includes an electrical power steering unit coupled to a mechanical control system, the mechanical control system including a steering wheel connected by a shaft to a mechanical cable assembly, the mechanical cable assembly configured to be actuated by the steering wheel to control a steering mechanism of the marine vessel. The electrical power steering unit includes an electric motor configured to apply a torque to the mechanical cable assembly. The system also includes a processor configured to control the electrical power steering unit to provide at least one of steering assist and control of the marine vessel.

In a ship steering system for an out-drive device including: an out-drive device; a hydraulic actuator configured to turn the out-drive device; a hydraulic controller configured to control the hydraulic actuator; a ship steering device configured to instruct a traveling direction to the hydraulic controller; and an emergency ship steering device capable of at least instructing the out-drive device to turn, the emergency ship steering device is capable of controlling the hydraulic actuator without involving the hydraulic controller.

In a ship steering system for an out-drive device including: an out-drive device; a hydraulic actuator configured to turn the out-drive device; a hydraulic controller configured to control the hydraulic actuator; a ship steering device configured to instruct a traveling direction to the hydraulic controller; and an emergency ship steering device capable of at least instructing the out-drive device to turn, the emergency ship steering device is capable of controlling the hydraulic actuator without involving the hydraulic controller.

A ship steering device includes a handle which is mechanically separated from a rudder mechanism, a steering angle detecting unit that detects a steering angle of the handle, a reaction force motor that generates reaction force torque to be applied to the handle, and a reaction force controller that controls, based on a steering characteristics map, the reaction force motor in such a way that the reaction force torque in accordance with the steering angle is obtained. The steering characteristics map has characteristics in such a way that the amount of change in an aiming steering torque relative to the steering angle is smaller in a second steering range where the steering angle is larger than that in a first steering range than the first steering region where the steering angle is set in advance from zero.

A ship steering device includes a handle which is mechanically separated from a rudder mechanism, a steering angle detecting unit that detects a steering angle of the handle, a reaction force motor that generates reaction force torque to be applied to the handle, and a reaction force controller that controls, based on a steering characteristics map, the reaction force motor in such a way that the reaction force torque in accordance with the steering angle is obtained. The steering characteristics map has characteristics in such a way that the amount of change in an aiming steering torque relative to the steering angle is smaller in a second steering range where the steering angle is larger than that in a first steering range than the first steering region where the steering angle is set in advance from zero.

In a moving center estimation method, a provisional moving center is set at a predetermined position in a neighborhood of an actual moving center of a hull. A sample thrust having a predetermined magnitude and direction is applied to the provisional moving center by driving the outboard motor, and a magnitude and direction of an angular acceleration generated in the hull by application of the sample thrust is detected. The magnitude of the angular acceleration is compared with a predetermined threshold value, and a position of the provisional moving center is changed and set so that the angular acceleration may converge in the threshold value, when the angular acceleration is larger than the threshold value.

In a moving center estimation method, a provisional moving center is set at a predetermined position in a neighborhood of an actual moving center of a hull. A sample thrust having a predetermined magnitude and direction is applied to the provisional moving center by driving the outboard motor, and a magnitude and direction of an angular acceleration generated in the hull by application of the sample thrust is detected. The magnitude of the angular acceleration is compared with a predetermined threshold value, and a position of the provisional moving center is changed and set so that the angular acceleration may converge in the threshold value, when the angular acceleration is larger than the threshold value.

A steering system for a marine vessel comprises a helm, a control head, and a joystick. The helm and control head may respectively provide user inputted steering commands and user inputted shift and throttle commands on a first CAN network. The joystick and the control head may respectively provide user inputted steering commands and user inputted shift and throttle commands on a second CAN network. The helm may provide user inputted steering commands on the first CAN network. The control head may provide user inputted shift and throttle commands on the second CAN network. The joystick may provide user inputted steering commands and user inputted shift and throttle commands on either the first CAN network or the second CAN network.