Control device for fluid loading and/or unloading system

A control device for controlling movement and positioning of a coupling which is located on a movable first end of a fluid transfer line of a marine loading system and is adapted for connection to a target duct, a second end of the fluid transfer line being fixed to a base and the coupling having at least three degrees of freedom relative to the base, the device comprising:

• at least three actuators, each of which controls movement of the coupling in a corresponding degree of freedom;
• means positioned on or adjacent at least one of the coupling and the target duct for providing information on the positioning of the coupling relative to the target duct;
• and
• calculating means for (a) calculating the positioning of the coupling relative to the target duct from the information on the positioning of the coupling relative to the target duct, (b) calculating control instructions for each of the actuators which will result in movement of the coupling toward the target duct, (c) applying said control instructions to the actuators to bring the coupling toward the target duct, and (d) repeating steps (a)-(c) as necessary until the coupling is located in a position for connection to the target duct;
• wherein the means for providing information on the positioning of the coupling relative to the target duct comprises a cord which is tensioned between the coupling and the target duct using a reel, and at least one of a cord angle sensor and an unwound cord length sensor.

A method for controlling positioning of a coupling which is located on a movable end of a fluid transfer line of a marine loading system and is adapted for connection to a target duct, the marine loading system comprising at least three actuators which each control movement of the coupling in a corresponding degree of freedom, the method comprising the steps of:

• determining the absolute positioning of the coupling in space;
• determining the absolute positioning of the target duct in space;
• calculating the positioning of the coupling relative to the target duct from the absolute positioning of the coupling and the target duct;
• calculating control instructions for each of the actuators which will result in a movement of the coupling toward the target duct;
• and
• applying said control instructions to the actuators to bring the coupling into a position for connection to the target duct.