An electric actuator comprises a housing and an output shaft reciprocatingly received by the housing. There is a screw assembly disposed within the housing and coupled to the output shaft. The screw assembly includes a plurality of annular rollers and a central screw received by the annular rollers. The annular rollers are rotatable about the central screw. There is a motor which includes a stator and a rotor. The rotor has an inner bore which engages the annular rollers. Rotation of the rotor causes the central screw to translate axially relative to the rotor and the output shaft to reciprocate relative to the housing.

An arrangement including a gearwheel connected to the propulsion unit, a steering electric motor operatively connected to the gearwheel and controlled by a drive, a force transmission arrangement including a clutch between the gearwheel and the steering electric motor, and a measurement unit for measuring rotational motion positioned at each side of the clutch. The steering electric motor is arranged to rotate the gearwheel and thereby also the propulsion unit. A difference in the output signals of the two measuring units indicating slipping of the clutch is detected. The steering electric motor is controlled to at least reduce the difference in the output signals when the difference exceeds a predetermined threshold.

An arrangement including a gearwheel connected to the propulsion unit, a steering electric motor operatively connected to the gearwheel and controlled by a drive, a force transmission arrangement including a clutch between the gearwheel and the steering electric motor, and a measurement unit for measuring rotational motion positioned at each side of the clutch. The steering electric motor is arranged to rotate the gearwheel and thereby also the propulsion unit. A difference in the output signals of the two measuring units indicating slipping of the clutch is detected. The steering electric motor is controlled to at least reduce the difference in the output signals when the difference exceeds a predetermined threshold.

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.

The invention concerns a computer-based system to control and steer high-speed boats by means of handlebar (23) and a plurality of control members (8, 9, 11) for a plurality of functions, critical for the manoeuvre, with a retained two-hand control of steering.

The invention concerns a computer-based system to control and steer high-speed boats by means of handlebar (23) and a plurality of control members (8, 9, 11) for a plurality of functions, critical for the manoeuvre, with a retained two-hand control of steering.

An electric actuator comprises a housing and an output shaft reciprocatingly received by the housing. There is a screw assembly disposed within the housing and coupled to the output shaft. The screw assembly includes a plurality of annular rollers and a central screw received by the annular rollers. The annular rollers are rotatable about the central screw. There is a motor which includes a stator and a rotor. The rotor has an inner bore which engages the annular rollers. Rotation of the rotor causes the central screw to translate axially relative to the rotor and the output shaft to reciprocate relative to the housing.

An electric actuator comprises a housing and an output shaft reciprocatingly received by the housing. There is a screw assembly disposed within the housing and coupled to the output shaft. The screw assembly includes a plurality of annular rollers and a central screw received by the annular rollers. The annular rollers are rotatable about the central screw. There is a motor which includes a stator and a rotor. The rotor has an inner bore which engages the annular rollers. Rotation of the rotor causes the central screw to translate axially relative to the rotor and the output shaft to reciprocate relative to the housing.

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.