From Helm to Rudder

Modes of Operation

• Non-Follow-up - A non-follow-up system facilitates solenoid valves controlling the steering actuator. Upon a steering request the valve(s) open completely, resulting in full force being applied to the rudder as long as input is given. Upon removal of the steering request the valve(s) closes again (time dependent control).
• Full Follow-up - A full follow-up system applies position feedback. The required rudder position is set on the steering controls, upon which the valves are opened to control the steering actuator. The actual position and requested position are continuously compared, resulting in automatic closure of the valves upon reaching the desired position (position dependent control).

Types of Valves

• Solenoid Valves - Solenoid valves are only capable of opening and closing completely. Once opened, full available power is applied to the rudder. Once closed, the rudder-applied power is terminated promptly. This results in a fast response type of characteristic.
• Proportional Valves - Proportional valves are capable of opening and closing gradually. This results in a smooth increase of force being applied to the rudder. Upon closure of the valves, power is gradually reduced to zero resulting in a deceleration of the actuator. This results in smooth and accurate steering characteristics.