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.

Claims

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] FIG. 1 is a diagrammatic view in perspective of a loading arm equipped with a control device according to the invention;

[0077] FIG. 2 is an synoptic diagram of the operation of the device according to FIG. 1;

[0078] FIG. 3 is a function diagram to represent the principle of operation of the control device according to FIGS. 1 and 2;

[0079] FIG. 4 is a diagrammatic view in perspective of another embodiment of a loading arm equipped with a control device according to the invention;

[0080] FIG. 5 is a diagrammatic view in perspective of another embodiment of a loading arm equipped with a control device according to the invention; and

[0081] FIGS. 6a and 6b are diagrammatic views in perspective of another embodiment of the loading arm equipped with a control device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0082] FIG. 1 is a very diagrammatic representation of a loading arm 2 equipped with a control device 1 according to the invention. The representation of the loading arm here is very simplified, and it should be recalled in this connection that the control device according to the invention adapts to any type of marine loading system, in particular to the loading systems described above.

[0083] The loading arm of FIG. 1 comprises a base 21 connected to a fluid tank which is located below the surface 22 on which the base is fixed. In the present case it is a quay, but in a variant it is a ship. At the apex of the base there is rotatably articulated a bent tube 23, on which is articulated in turn a first tube referred to as an inner tube 24 which is articulated at its opposite end with a second tube referred to as an outer tube 25. The end of the outer tube carries a coupling 26 adapted to be connected to a target duct 35, disposed in the present example on a ship 36 represented very diagrammatically.

[0084] In the embodiment represented, in a manner known per se, the coupling has three degrees of freedom in rotation relative to the end of the outer tube. In the present embodiment, these three rotations are free, such that an operator may freely adjust the angle of the coupling during the final phase of approach for the connection of the coupling to the target pipe.

[0085] In an alternative embodiment, not shown, one or more of these rotations are controlled by actuators and connected to a command interface to enable the operator directly to control the rotations on the final approach of the coupling.

[0086] In a manner known per se, the coupling in the present embodiment has locking claws 31 which are closed by an actuator 30 represented very diagrammatically to hold the coupling 26 around the target duct 35, once they are connected.

[0087] Generally, this type of loading arm is known per se, and will not be described in more detail here. It will moreover be recalled that the control device according to the invention adapts to all the marine loading systems, and that the adaptation of the control device according to the invention to any other type of loading system, in particular one of the systems described above, is within the capability of the person skilled in the art.

[0088] In the device according to the invention as represented diagrammatically in FIG. 1, actuators 27, 28, 29 are provided at each of the three articulations of the loading arm (symbolized by the double arrows A, B, C). More specifically, a first actuator 27 is provided between the apex of the base 21 and the bent tube 23, to pivot the latter horizontally relative to the base, a second actuator 28 is provided between the end of the bent tube 23 and the inner tube 24 so as to pivot the inner tube vertically, and a third actuator 29 is provided between the inner tube 24 and the outer tube 25 to make the latter pivot vertically.

[0089] The three actuators 27, 28, 29 are hydraulic jacks here represented very diagrammatically in FIG. 1. In a variant not illustrated, one or more of the hydraulic jacks are replaced by hydraulic motors. According to another variant not illustrated, the actuators are electric or pneumatic motors.

[0090] The target duct 35 provided here on a ship 36 represented very diagrammatically is provided with a box 34 enclosing a means for providing information on positioning of the target duct which is, in the present embodiment, a device of a system for global positioning of the GPS type, enabling an absolute position to be given, and more particularly the spatial coordinates of the free end of the target duct.

[0091] The same applies for the coupling 26, which comprises a box 33 enclosing a device of a system for global positioning of the GPS type, enabling an absolute position to be given, and more particularly the spatial coordinates of the connecting end of the coupling.

[0092] The calculating means of the control device are combined into a calculator 41 disposed in an electrical control cabinet 40.

[0093] A hydraulic power unit 42 is provided to supply the actuators with the hydraulic energy necessary for their operation. It is controlled by the calculator 41.

[0094] The GPS boxes 33 and 34 are each respectively provided with an emitting device 33A and 34A to emit a signal comprising positioning information. The calculator 41 is linked to a receiver device 40A adapted to receive said signals from the emitters 33A and 34A. The control device furthermore comprises a command interface 60 for an operator.

[0095] Alternatively, the box 33 is positioned on a member immediately neighboring the coupling, for example one of the members articulated to the end of the arm, the calculating means being adapted to extrapolate the information on positioning of the coupling relative to the information provided by the box.

[0096] As can be seen more particularly in FIG. 2, in the synoptic diagram of the operation of the device according to FIG. 1, the calculator 41 is linked to the receiver device 40A, which is a radio receiver adapted to communicate with the radio transmitter devices 33A and 34A respectively linked to the GPS boxes 33 and 34 of the coupling and of the target duct. The GPS boxes thus provide the calculator with information on the positioning of the coupling and of the target duct.

[0097] In an alternative embodiment, the GPS boxes are devices designed to communicate with each other so as to directly provide information on the relative position of the coupling relative to the target duct, to the calculator.

[0098] The loading arm 2 is equipped with actuators 27, 28, 29, which are controlled by valves that are themselves controlled by the calculator. The hydraulic power unit 42 supplies the actuators via said valves with the hydraulic energy necessary for their operation. The hydraulic power unit 42 is controlled by the calculator via power relay 43 to control the starting and stopping of the hydraulic power unit. The hydraulic power unit comprises a pump (not represented) adapted to pump a hydraulic fluid to supply the actuators.

[0099] The command interface 60 is linked to the calculator to enable an operator to command the connection of the coupling to the target duct.

[0100] As can be seen in FIGS. 2 and 3, when the operator wishes to connect the coupling to the target duct, he actuates a button 61 on the command interface 60 to order the connection. A signal corresponding to his order is then sent to the calculator. The calculator then launches the automatic connection procedure.

[0101] The calculator receives, via the radio receiver 40A, the information on positioning of the coupling and of the target duct from the respective GPS boxes 33 and 34. Alternatively, in another embodiment, the calculator receives the information by cable directly from the GPS boxes. According to an alternative embodiment, the GPS box 34 situated on the ship sends the information on positioning of the target duct to the GPS box 33 of the loading arm which calculates the relative positioning of the coupling relative to the target duct and sends back the result to the calculator by radio or wire link.

[0102] The calculator converts this information into spatial coordinates to obtain the relative position of the coupling relative to the target duct.

[0103] On the basis of the information on the relative position of the coupling relative to the target duct, the calculator calculates the distances that remain between the coupling and the target duct along the X, Y and Z axes, which are diagrammatically represented in FIG. 1.

[0104] If these three distances are not zero, or equal to distances parameterized as reference distances that are known for the connection, the calculator calculates control instructions for each of the actuators 27, 28, 29 of the arm such that their combined movements result in a movement of the coupling aimed at bringing the coupling closer to the target duct along the three axes. The calculator then applies the control instructions calculated for each actuator to the actuators 27, 28, 29 via the corresponding valves. Once the instructions have been executed by the actuators, the calculator again calculates the distances remaining between the coupling and the target duct along the X, Y and Z axes. If these distances are not still zero or equal to the parameterized distances (for example, when the sea conditions are bad) the calculator recommences the calculations of the instructions for the actuators and applies them until the distances are zero or equal to the parameterized distances. In other words, the calculator applies control instructions, at the order of the operator via the command interface 60, to bring the coupling towards the target duct until it is presented in front of the target duct in a position for connection.

[0105] If the three distances are zero or equal to the parameterized distances, it means that the coupling is located facing the target duct in position for connection. The calculator then sends a control instruction to the actuator 30 of the coupling to clamp the coupling to the target duct, and then an instruction to disengage the actuators 27, 28, 29 of the arm, so as to make the movements of the arm free once the coupling has been connected and clamped to the target duct.

[0106] Lastly, an indicator light 62 indicates to the operator on the command interface that the automatic connection has ended successfully.

[0107] An emergency stop button for stopping the automatic connection procedure, not shown, is provided on the command interface 60.

[0108] In a variant, not shown, other indicators are provided on the command interface to signal to the operator various malfunctions or problems in the automatic connection process.

[0109] According to an embodiment not represented, the means for providing information on positioning of the coupling is adapted to cooperate directly with a means for providing information on positioning of the base disposed on the base or on a member that is fixed relative thereto to provide, on the basis of the information on positioning of the base, information on relative positioning of the coupling directly relative to the base. This may, for example, be the same GPS box 33 cooperating with another GPS box disposed on the base. Alternatively, if the base is fixed to a quay, the means for providing information on positioning of the coupling is adapted to provide information on absolute positioning of the coupling in space, for example via a GPS box and, with the base having a position fixed in space, the calculator is adapted to calculate, on the basis of the GPS coordinates of the fixed base and the GPS coordinates of the coupling mobile in space, the relative positioning of the coupling directly relative to the base. In this embodiment, the calculator calculates in real time information on positioning of the coupling relative to the base according to the movements of the coupling and the information provided by the means for providing information on positioning of the coupling. The calculator is parameterized with data defining at least one authorized zone for positioning of the coupling and is adapted to verify in real time whether the coupling is in the authorized zone. In the opposite case, the calculator is adapted to emit an alarm when the coupling leaves the corresponding authorized zone. Advantageously, according to a variant, the calculating means are adapted to stop the command for automatic connection of the coupling when such an alarm is emitted. Advantageously, the fact of providing such authorized zones or working zones makes it possible to avoid a risk of damage to the system in particular by rupture or interference when the coupling is moved too far from the base during extension or rotation.

[0110] In this case, the calculator is programmable so as to define working zones and/or forbidden zones which may be parameterized by the operator according to each loading or unloading operation of fluid products. This makes it possible, for example, to adapt the automatic connection procedure to different ships which may have different possible collisions zones.

[0111] Light or sound emitting indicators are provided to warn the operator of the crossing of an authorized zone boundary.

[0112] In an embodiment that is not represented, several marine loading systems are connected to the same calculator 40, and a selector is provided at the command interface to selectively control the connection of one or other of the loading systems linked to the calculator. Working zones corresponding to the neighboring loading system are programmed so as to avoid collisions between the different loading systems.

[0113] In an alternative embodiment not represented, the three degrees of rotational freedom of the coupling at its end relative to the end of the outer tube are controlled by actuators, for example hydraulic motors or jacks. The device is provided with means for providing information on angular orientation of the coupling, and means for providing information on angular orientation of the target duct, for example pendulum sensors. Suitable calculating means are provided to calculate, according to the information provided by the means for providing information on angular orientation of the coupling and of the target duct, control instructions given to the actuators in order for the angular orientation of the coupling, in position for connection, to be substantially the same as the angular orientation of the target duct. Thus, the connection is made more precise and more reliable in that, on connection, the target duct and the coupling are aligned. This makes it possible in particular to reduce the risks of damage to the seals between the coupling and the target duct.

[0114] In all cases, when the connection has been made, that is to say when the coupling has been clamped onto the target duct, the calculator sends a disengage instruction to the actuators so as to make the movements of the system free in order to enable the coupling to freely follow the movements of the target duct.

[0115] FIG. 4 is a diagrammatic view in perspective of another embodiment of a loading arm equipped with a control device according to the invention, in which the means for providing information on positioning of the coupling is a camera mounted on the coupling. The representation of the coupling has been simplified for reasons of clarity.

[0116] A target 71 is disposed on the target duct 35. The camera is designed to focus on the target and provide the calculator with an image of the target. On the basis of that image, the calculator is adapted to calculate the relative positioning of the coupling relative to the target duct.

[0117] To that end, the calculator is provided with an algorithm for processing the image and for shape recognition in order to determine the distance and the angle so as to deduce therefrom the relative positioning of the coupling relative to the target duct. For the calculation of the distance, the algorithm uses the principle whereby the greater the distance between the coupling and the target duct, the smaller the image of the target, and for the calculation of the angle, the principle whereby, for a circular target, when the coupling is along the axis of the target duct, the image of the target is circular, and when the coupling is axially offset relative to the target duct, the image of the target is elliptical.

[0118] In another variant, several cameras are disposed to focus on the same target and provide several images to the calculator, the latter being adapted to process all these images to calculate the relative positioning of the coupling relative to the target duct.

[0119] In another embodiment, a camera is mounted on a motorized support, itself controlled by calculating means to pivot in order to be continuously oriented towards the target and enabling the angular orientation of the camera relative to the axis of the coupling to be known at any time, the calculating means being adapted to process this angular orientation information and the image sent by the camera to control the movement of the coupling to a position for connection.

[0120] Preferably, for reasons of performance, the target is a reflective sighting device.

[0121] According to an advantageous variant not illustrated, the target may be omitted, and the camera designed so as to take the free end of the target duct itself as a target. This embodiment makes it possible in particular to dispense with having a sighting device or target on the target duct. Thus, for example, if the target duct is on a boat, it will be possible for the device to adapt to all boats of which the ducts are compatible with the coupling, whether they are equipped with a target or not.

[0122] Apart from the differences described above, structurally, and functionally, this embodiment is the same as the embodiment of FIGS. 1 to 3, and it will not therefore be described in more detail here.

[0123] According to another embodiment not illustrated, the camera may be disposed on the target duct or on the bridge of a boat so as to be fixed or motorized relative to the bridge of the boat and be oriented to provide the calculator with an image of the coupling, so as to enable the calculator to calculate using the same principle of the relative positioning of the coupling relative to the target duct.

[0124] FIG. 5 is a diagrammatic view in perspective of another embodiment of a loading arm equipped with a control device according to the invention, in which the means for providing information on positioning of the coupling is a tensioned cord between the target duct and the coupling.

[0125] At one of its ends, the cord 75 has means for fastening to the target duct. The other end of the cord is attached to the drum of a reel 72, itself mounted on the coupling. The reel comprises an incremental sensor 73 making it possible to determine the length of cord unwound, this information being sent to the calculator which deduces therefrom the distance between the coupling and the target duct.

[0126] Furthermore, an angle sensor 74 of the cord is provided for the cord 75, in order to determine an inclination of the cord relative to at least two reference angles.

[0127] In this way, it is possible to determine the relative positioning of the coupling relative to the target duct on the basis of the two reference angles and the distance of the unwound cord. The angle sensor is for example a sensor using an inclinometer or a laser to determine the inclination of the cord relative to said at least two reference angles.

[0128] As a variant, the device is provided with a plurality of reels of which the cords are attached at separate places, such that on the basis solely of the information on the unwound distances provided by the reel sensors, the calculator calculates the angles and the distance for the relative positioning of the coupling relative to the target duct.

[0129] On putting it in place, the cord is first of all fastened to a projectile which is thrown by means known to the person skilled in the art from the quay to the ship, or from the ship to another ship. An operator then fastens the free end of the cord to a place provided on the target duct. The operator may then launch the procedure for automatic connection using the same principle as in the embodiment of FIGS. 1 to 3.

[0130] According to a variant not illustrated, the reel is provided with a cord rupture detector to suspend the connection procedure in case of rupture of the cord and to trigger a procedure for retraction of the arm. A corresponding warning is then communicated to the operator via the command interface, for example by an indicator light indicating the breakage of the cord.

[0131] FIGS. 6a and 6b are diagrammatic views in perspective of another embodiment of the loading arm equipped with a control device according to the invention, in which two different means of providing information on positioning of the coupling are used. One of the means makes it possible to determine the positioning of the coupling with greater precision than the other. The calculator 40 is adapted to use the means for positioning of the coupling having the least precision to perform a rough approach for the purpose of the connection of the coupling to the target duct and then, when the distance between the coupling and the target duct becomes less than a predefined distance, the calculator uses the coupling positioning information means having the greatest precision to perform the final phase of the approach for the purpose of presenting the coupling in front of the target duct in a position for connection. In practice, in a first phase the calculator uses positioning information from the GPS boxes 33 and 34 according to the same principle as described earlier, and in a second phase the calculator uses positioning information from a laser device comprising a laser emitter 77, and a target 76, the device being adapted to determine, by virtue of a laser beam 78, the relative positioning of the coupling relative to the target duct during the final phase of the approach aiming to present the coupling in front of the target duct in a position for connection. Thus, advantageously, the device takes advantage of the features of the different means for providing information on positioning of the coupling and of the target duct by matching their degrees of precision with the distance remaining to reach a position for connection. The precision of the connection is optimized thereby. As a variant, the laser device is replaced by an infra-red device.

[0132] Generally, in a variant that is not illustrated which applies to all the embodiments described above, several arms are controlled by the same calculator. A selector provided on the command interface enables a plurality of loading arms, linked to the same calculator, to be controlled using the same principle and with the same command interface.

[0133] In another general variant that is not illustrated, the command interface is a remote control unit provided with a transmitter for wireless communication with a receiver linked to the calculator in the electrical control cabinet. The transmitter and receiver communicate by radio waves. As a variant, the transmitter and the receiver communicate by optical waves, for example infrared waves.

[0134] In a variant not illustrated, at least one of the actuators of the loading arm is a proportional control actuator. In this variant, the calculator is adapted to control the proportional control actuators. Advantageously, the use of a proportional control actuator makes it possible to have movement of the coupling that is direct and rectilinear, and thus shorter and faster. This enables the time for the automatic connection procedure to be reduced.

[0135] Numerous other variants are possible according to circumstances, and in this connection it is to be noted that that the invention is not limited to the examples represented and described.