Control Device for Fluid Loading and/or Unloading System

Abstract

1. A marine loading arm which includes at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct. The coupling has at least three degrees of freedom relative to the base and the marine loading arm further includes a control device for controlling the movement and positioning of the coupling. The control device has at least three actuators, each of which controls movement of the coupling in a corresponding degree of freedom and each of which comprises an electric motor which is provided at an articulation of the loading arm providing one of the degrees of freedom. The control device further includes a first global positioning system device positioned on or adjacent the coupling for providing information on the absolute positioning of the coupling in space.

1 . A marine loading arm comprising:
 at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct, the coupling having at least three degrees of freedom relative to the base; and   a control device for controlling the movement and positioning of the coupling, the control device comprising at least three actuators, each of which is an electric motor which controls movement of the coupling in a corresponding degree of freedom and is provided at an articulation of the loading arm that provides the corresponding degree of freedom;   the control device further comprising a first global positioning system device positioned on or adjacent the coupling for providing information on the absolute positioning of the coupling in space.   
     
     
         2 . The marine loading arm according to  claim 1 , wherein the control device further comprises calculating means for (a) calculating the positioning of the coupling relative to the target duct on the basis of information on the absolute positioning of the target duct in space and the information on the absolute positioning of the coupling in space, (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. 
     
     
         3 . The marine loading arm according to  claim 1 , wherein the coupling is articulated with three degrees of rotational freedom relative to the movable end of the fluid transfer line, and wherein the control device further comprises:
 at least one additional actuator for controlling movement of the coupling in at least one of the three rotational degrees of freedom, the at least one additional actuator comprising an electric motor;   means for providing information on the angular orientation of the coupling; and   means for providing information on the angular orientation of the target duct;   wherein the calculating means is adapted to calculate, on the basis of the information on the angular orientation of the coupling and on the angular orientation of the target duct, control instructions for the at least one additional actuator in order to make the angular orientation of the coupling in the position for connection substantially the same as the angular orientation of the target duct.   
     
     
         4 . The marine loading arm according to  claim 1 , further comprising a clamping actuator for enabling the coupling to be clamped and unclamped, wherein once the coupling is in the position for connection, the calculating means applies a control instruction to said clamping actuator to clamp the coupling onto the target duct. 
     
     
         5 . The marine loading arm according to  claim 4 , wherein once the coupling has been clamped onto the target duct, the calculating means applies an instruction to disengage the actuators. 
     
     
         6 . The marine loading arm according to  claim 1 , further comprising a second global positioning system device positioned on or adjacent the target duct for providing the information on the absolute positioning of the target duct in space. 
     
     
         7 . The marine loading arm according to  claim 6 , wherein the first and second global positioning system devices comprise means for communicating with each other and means for calculating and providing information on the positioning of the coupling relative to the target duct. 
     
     
         8 . A marine loading arm comprising:
 at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct, the coupling having at least three degrees of freedom relative to the base; and   a control device for controlling the movement and positioning of the coupling, the control device comprising at least three actuators, each of which is an electric motor which controls movement of the coupling in a corresponding degree of freedom and is provided at an articulation of the loading arm that provides the corresponding degree of freedom;   the control device further comprising means positioned on or adjacent at least one of the coupling and the target duct for providing information on the positioning of the coupling;   wherein the coupling positioning information means includes an optical device which is fixed relative to one of the coupling and the target duct and is adapted to emit a luminous beam towards the other of the coupling and the target duct, detect the reflected beam, measure the travel time of the beam and deduce therefrom the positioning of the coupling relative to the target duct.   
     
     
         9 . The marine loading arm according to  claim 8 , wherein the control device further comprises calculating means for (a) calculating the positioning of the coupling relative to the target duct on the basis of the information on the positioning of the coupling, (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. 
     
     
         10 . A marine loading arm comprising:
 at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct, the coupling having at least three degrees of freedom relative to the base; and   a control device for controlling the movement and positioning of the coupling, the control device comprising at least three actuators, each of which is an electric motor which controls movement of the coupling in a corresponding degree of freedom and is provided at an articulation of the loading arm that provides the corresponding degree of freedom;   the control device further comprising a camera which is fixed relative to one of the coupling and the target duct and is adapted to provide an image of the other of the coupling and the target duct or of a target which is fixed relative to the other of the coupling and the target duct.   
     
     
         11 . The marine loading arm according to  claim 10 , wherein the control device further comprises calculating means which is adapted to: (a) process the image provided by the camera and calculate therefrom the positioning of the coupling relative to the target duct, (b) calculate control instructions for each of the actuators which will result in movement of the coupling toward the target duct, (c) apply said control instructions to the actuators to bring the coupling toward the target duct, and (d) repeat steps (a)-(c) as necessary until the coupling is located in a position for connection to the target duct. 
     
     
         12 . A marine loading arm comprising:
 at least one fluid transfer line having a fixed line end fixed to a base and a moveable line end provided with a coupling adapted for connection to a target duct, the coupling having at least three degrees of freedom relative to the base; and   a control device for controlling the movement and positioning of the coupling, the control device comprising at least three actuators, each of which is an electric motor which controls movement of the coupling in a corresponding degree of freedom and is provided at an articulation of the loading arm that provides the corresponding degree of freedom;   the control device further comprising 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;   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.   
     
     
         13 . The marine loading arm according to  claim 12 , wherein the control device further comprises calculating means for (a) calculating the positioning of the coupling relative to the target duct on the basis of 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. 
     
     
         14 . The marine loading arm according to  claim 1 , wherein at least one of the actuators comprises a proportional control actuator. 
     
     
         15 . The marine loading arm according to  claim 2 , further comprising at least a second means for providing information on the positioning of the coupling, said second means being adapted to determine the positioning of the coupling with greater precision than the first global positioning device, wherein the calculating means ( 41 ) uses the information on the positioning of the coupling from the second means when the distance between the coupling and the target duct is less than a predefined distance. 
     
     
         16 . The marine loading arm according to  claim 2 , further comprising means positioned on or adjacent the base for providing information on the absolute positioning of the base in space, wherein the calculating means is adapted to calculate in real time from the information on the positioning of the coupling and the information on the positioning of the base, information on the positioning of the coupling relative to the base, compare the information on the positioning of the coupling relative to the base to data defining at least one authorized positioning zone for the coupling, and trigger a perceptible alarm signal when the coupling leaves the authorized positioning zone. 
     
     
         17 . The marine loading arm according to  claim 16 , wherein the calculating means is adapted to stop the application of the control instructions to the actuators when the coupling leaves the authorized positioning zone.