GB2616619A

GB2616619A - Apparatus for deploying and recovering an object to and from a platform and method for the same

Info

Publication number: GB2616619A
Application number: GB2203531.5A
Authority: GB
Inventors: William Kirkley David; Glen Back Peter
Original assignee: Submarine Tech Ltd
Current assignee: Submarine Tech Ltd
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2023-09-20
Also published as: GB202203531D0

Abstract

A system (2, Fig 1) mounted on a host platform (10, Fig 1) located in, on or adjacent a body of water for moving an object 26 from a first position to a second position. The system comprises an assembly 102 for supporting and moving an object that comprises a base 110 for mounting on a host platform, a support assembly 130 having a proximal end (132, Fig 2b) mounted on the base and a distal end (134, Fig 2b) for connecting to the object, an actuation system 160 for moving the distal end of the support assembly and a movement control system (20, Fig 2b) configured to receive data regarding movement of the host platform and data regarding the motion of the object when the object is moving independently of the host platform. The movement control system being further configured to provide control signals to the actuation system for moving the distal end of the support assembly. The movement control system controlling the distal end of the support assembly to move along a path between the first position and the second position. Methods for deploying and recovering an object from and to a platform are also provided.

Description

APPARATUS FOR DEPLOYING AND RECOVERING AN OBJECT TO AND FROM A PLATFORM AND METHOD FOR THE SAME

The present invention relates to an apparatus for deploying an object, such as a remote vehicle from a platform, such as a vessel, and recovering the object to the same or other platform. The present invention also relates to a method of accomplishing the same.

Many offshore operations require the deployment and recovery of objects from a host platform on a body of water, such as a lake, sea or ocean. Many of these operations require deployment from and recovery to a host platform that is itself floating, such as a boat or ship. Examples of objects that must be deployed and recovered include remote vehicles, such as remotely operated vehicles (ROV's) and autonomous underwater vehicles (AUV's). The launch and recovery of floating objects is complicated by the relative motion between the floating object and the host platform. As will be appreciated, the operations become more complicated as the conditions, such as swell and wind, become more severe.

A number of handling systems for deploying and/or recovering floating objects from the water have been proposed and employed in the past. However, these systems typically have one or more aspects which restrict their use to only certain environmental conditions, such as fair or fine weather conditions. Many of the known systems require the manual intervention of an operator or other crew member during at least a part of the deployment or recovery operation. This renders such systems unsuitable for use in many situations, for example when the host platform is an autonomous surface vehicle (ASV).

There is therefore a need for an improved system and method for deploying and recovering objects, such as remote vehicles, from and to a host platform or other platform, such as a floating vessel.

In a first aspect, the present invention provides a system for moving an object from a first position to a second position, wherein the system is configured to be mounted on a host platform located in, on or adjacent a body of water, the system comprising: an assembly for supporting and moving an object, the assembly comprising: a base for mounting on a host platform; a support assembly having a proximal end mounted on the base and a distal end for connecting to the object, the distal end of the support assembly being moveable relative to the base between a position in which the distal end of the support assembly is engageable with the object in the first position and a position in which the distal end of the support assembly is engageable with the io object in the second position, the distal end of the support assembly comprising an engagement assembly for releasably engaging the support assembly with the object; and an actuation system for moving the distal end of the support assembly; the system further comprising: is a movement control system configured to receive data regarding movement of the host platform and data regarding the motion of the object when the object is moving independently of the host platform, the movement control system further configured to provide control signals to the actuation system for moving the distal end of the support assembly, the movement control system controlling the distal end of the support assembly to move along a path between the first position and the second position independently of the movement of the host platform or synchronised with the movement of the object when the object is moving independently of the host platform.

In a further aspect, the present invention provides a method for deploying an object from a first position to a second position, the method comprising: providing a support assembly on a host platform, the support assembly having a proximal end mounted to the host platform and a distal end, the distal end of the support assembly being moveable relative to the host platform; releasably engaging the distal end of the support assembly with the object; moving the distal end of the support assembly from the first position to the second position, whereby the object is moved along a path independent of movement of the host platform; and releasing the engagement between the distal end of the support assembly with the object at the second position.

In a still further aspect, the present invention provides a method for recovering an object from a second position to a first position, the method comprising: providing a support assembly on a host platform, the support assembly having a proximal end mounted to the host platform and a distal end, the distal end of is the support assembly being moveable relative to the host platform; synchronising the movement of the distal end of the support assembly with the movement of the object in response to data received regarding the relative movement of the host platform and the object; engaging the distal end of the support assembly with the object; and moving the object from the second position to the first position.

The present invention relates to a system and methods for moving an object between a first position and a second position. The system is for mounting on a host platform that is located on, in or adjacent a body of water.

The host platform may be a moving platform, in particular a floating platform located at the surface of the body of water, for example a vessel or a buoy.

Alternatively, the host platform may be a fixed platform, for example a platform disposed in the body of water and fixed to the bed of the body of water or a platform adjacent a body of water, for example a dock or quay. Examples of fixed platforms include a fixed structure in an offshore oil and gas field or a tower of an offshore wind turbine fixed to the seabed.

The system and methods of the present invention are particularly advantageous when the host platform is a floating platform, in particular a vessel, and are used to deploy and recover objects from and to the floating platform, for example a vessel.

The system of the present invention is for moving an object between a first position and a second position.

The first position may be a position on the host platform where the object is located, for example to be stowed. Alternatively, the first position may be on a platform other than the host platform, for example a floating platform, such as a vessel floating in a body of water or a buoy, or a fixed platform, for example the tower of an offshore wind turbine fixed to the seabed.

The second position may be a position in a body of water adjacent the host platform or on which the host platform is floating. Alternatively, the second position may be a platform other than the host platform, for example a floating platform, such as a vessel floating in a body of water or a buoy, or a fixed platform, for example the tower of an offshore wind turbine fixed to the seabed.

The system and methods of the present invention are particularly advantageous when used to deploy an object from a host platform into a body of water and/or recovering an object to the host platform from the body of water.

The present invention may be employed to move a wide range of objects.

The object may be a floating object. In this respect, references herein to a 'floating object' are references to an object that is subject to movement by the body of water, for example movement as a result of waves, currents and/or swell in the body of water. The floating object may be floating directly in the water. Examples of such floating objects include small water borne craft, such as RIBs, remote vehicles, such as remotely operated vehicles (ROVs), autonomous underwater vehicles (AUVs) and equipment used for measurements at or below the surface of the water. The object may be on or within a platform, such as a vessel or buoy, that itself is floating on the body of the water, or on or in a fixed platform, such as the tower of an offshore wind turbine fixed to the seabed. Examples of objects include items of cargo and personnel to be transferred from one platform, such as a vessel or fixed structure, to another platform, such as a vessel or fixed structure.

The present invention is particularly advantageous in the deployment and recovery of remote vehicles, for example autonomous or semi-autonomous vehicles, such as remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs), in particular from floating platforms, such as a vessel, or a fixed platform.

The present invention provides, in a first aspect, a system for deploying an object from and recovering an object to a host platform. The system comprises an assembly. In operation, the assembly is employed to lift and move the object between the first position and the second position.

The assembly comprises a base for mounting to the host platform. The base may be any component or assembly of components that can secure the assembly to the host platform.

In one preferred embodiment, the base comprises a fixed base assembly for securing to the host platform and a moveable base assembly mounted to the fixed base assembly for movement relative to the fixed base assembly. Preferably, the moveable base assembly is rotatably mounted to the fixed base assembly. Wth the host platform at rest, the moveable base assembly preferably moves in a substantially horizontal plane. In an alternative embodiment, the moveable base assembly is mounted to the fixed base assembly by a gimbal and rotatable with respect to the fixed base assembly.

The assembly further comprises a support assembly. The support assembly has a proximal end and a distal end. The proximal end of the support assembly is mounted to the base. In embodiments in which the base comprises a fixed base assembly and a moveable base assembly the proximal end of the support assembly is mounted to the moveable base assembly. The distal end of the support assembly is moveable relative to the host platform and the base to which the proximal end of the support assembly is mounted. The distal end of the support assembly is moveable by an actuation system between a first position, in which the distal end is engageable with an floating object on or within the host platform, and a second io position, in which the distal end is in a position to release the object being deployed into or on the water or engage with a floating vessel. The distal end of the support assembly is moved between the first and second positions by the actuation system in response to signals received from a movement control system, as described in more detail hereinbelow.

The support assembly preferably comprises one or more support members.

In one embodiment, the support assembly has a single support member. The single support member is mounted at its proximal end to the base. In embodiments, in which the base comprises a fixed base assembly and a rotatable base assembly, the support member is preferably mounted to the rotatable base assembly.

The support member may have any suitable form. In one embodiment, the support member is an elongate member or arm. Alternatively, the support member may comprise a frame member, for example a rectangular or triangular frame member. For example, the support member may comprise an A-frame having a wide end and a narrow end, preferably with the A-frame mounted with its wide end proximal to the host platform and the narrow end distal of the host platform.

In an alternative embodiment, the support assembly comprises a plurality of support members, preferably wherein the support members are connected in an articulated arrangement. By providing the support assembly with a plurality of support members, the support assembly is able to be manoeuvred to allow its distal end to access any position within a volume of space defined by the limits of the movement of the distal end.

In one embodiment, the support assembly comprises an articulated assembly having a first support member mounted to the base, preferably pivotally mounted to the base, and extending from the proximal end of the support assembly and a second support member pivotally mounted to the end of the first support member and extending to the distal end of the support assembly.

Alternatively, the support assembly may comprise an articulated assembly having more than two support members, for example an articulated assembly having a first support member extending from the proximal end of the support assembly, a second support member pivotally mounted to and extending from the first support member and a third support member pivotally mounted to an extending from the second support member to the distal end of the support assembly. In one preferred embodiment, the support assembly comprises an articulated assembly comprising a first support member pivotally mounted to the base and extending in the distal direction, a second support member pivotally connected to the end of the first support member and extending distally, a third support member pivotally connected to the end of the second support member and extending distally, and a fourth support member pivotally connected to the end of the third member and extending to the distal end of the support assembly.

In embodiments where the support assembly is pivotally mounted to the base at its proximal end, the pivot mounting preferably allows the support assembly to move relative to the base about a substantially horizontal axis, when the base and the host platform are at rest.

Each support member may have any suitable form. In one preferred embodiment, each support member comprises an elongate arm.

The support assembly comprising one or more support members is mounted at its proximal end to the base. The mounting allows the one or more support members to move in at least one plane or direction relative to the host platform. In particular, the support assembly may be pivotally mounted to the base at its proximal end to allow the distal end of the support assembly to be raised and lowered in one plane, thereby moving the distal end between the first and second positions, with the distal end being in the first position when raised and in the second position when lowered. Wth the host platform at rest, the support member is preferably mounted to the base so as to allow the distal end to be raised and lowered in a substantially vertical plane.

Alternatively, the support assembly comprising one or more support members may be mounted to the host platform so as to allow the distal end to be raised and lowered in a first plane, as just described, and the proximal end rotated about the io mounting to the host platform in a second plane, perpendicular to the first plane. With the host platform at rest, the first plane is preferably substantially vertical and the second plane is preferably substantially horizontal. In embodiments in which the base has a moveable base member rotatably mounted on a fixed base member, this may be achieved by mounting the proximal end of the support member to the moveable is base member.

As a further alternative, the support assembly comprising one or more support members may be mounted to the host platform so as to allow the distal end to be raised and lowered in a first plane, as hereinbefore described, the proximal end to be rotated about the mounting in a second plane perpendicular to the first plane, as just described, and the support member rotated about the mounting in a third plane, wherein the third plane is perpendicular to the first plane and the second plane. In embodiments in which the base has a moveable base member mounted on a fixed base member by a gimbal and able to rotate relative to the fixed base member, this may be achieved by mounting the proximal end of the support assembly to the moveable base member.

Suitable articulated support assemblies having a plurality of support members are known in the art. An example of a known support assembly is the Neptune 20M+ system available from Submarine Technology Limited, United Kingdom.

A support assembly suitable for use in the system of the present invention is 30 described and shown in GB 2,336,828 A. The support assembly comprises a base with a fixed part to be mounted in use on the host platform and an articulated assembly having two support members for controlled movement in three mutually perpendicular planes or directions relative to the fixed part of the base. A support arm assembly is mounted at one end on the articulated assembly for luffing and reach movement.

WO 2021/239728 discloses a support assembly suitable for use in the system of the present invention. The support assembly is similar to that of GB 2,336,828 A and comprises a base having a stationary base part and a moveable base part rotatable relative to the stationary base part about a substantially vertical axis. The support assembly further comprises an arm assembly comprising two support members mounted to the moveable base part and moveable about a substantially horizontal axis.

It is especially preferred that the assembly, preferably the base and the support assembly, is configured to allow the distal end of the support assembly to is have a freedom of movement that allows the movement of the distal end to compensate for movement of the host platform in six degrees, namely heave, pitch, roll, yaw, surge and sway.

The support assembly further comprises an engagement assembly. The engagement assembly is disposed at the distal end of the support assembly and is configured to releasably engage the distal end of the support assembly with the object. Any suitable assembly for releasable engaging the distal end of the support assembly with the object may be employed. Examples of suitable assemblies include mechanical engagement assemblies, in which the distal end of the support assembly is provided with a latch for releasably connecting to a complementary form on the exterior of the object. Alternative engagement assemblies include, for example, electromagnetic assemblies.

In one preferred embodiment, one of the distal end of the support assembly and the object is provided with a male latch member and the other of the distal end of the support assembly and the object is provided with a female latch member, wherein the female latch member is releasably engageable with the male latch member. The male latch member may have any suitable form. In one preferred embodiment, the male latch member comprises a rounded latch portion, preferably a spherical cap or spherical dome. The female latch member may have any suitable form complementary to the male latch member. In one preferred embodiment, the female latch member comprises a receiver for receiving the male latch member, the receiver provided with one or more moveable locking fingers for engaging with a portion of the male latch member, for example a recess or groove formed in the male latch member. The locking fingers may be moved into and/or out of engagement with the male latch member by any suitable means, for example hydraulically or electrically, such as by to one or more solenoids. The female latch member preferably comprises a guide for guiding the male latch member into engagement with the locking fingers. The guide may have any suitable form, for example conical.

The assembly further comprises an actuation system. In use, the actuation system is operable to move the one or more support members of the support system. The actuation system comprises one or more actuators for moving one or more support members of the support assembly relative to each other and with respect to the base on which the support assembly is mounted. In addition, in embodiments in which the base comprises a fixed base assembly and a moveable base assembly, which is moveable, for example rotatable, relative to the fixed base assembly, the actuation system also operates to move the moveable base assembly relative to the fixed base assembly.

Suitable actuators are known in the art and include electric actuators and hydraulic actuators. Hydraulic actuators, such as hydraulic rams, are particularly suitable for use in the present invention.

The system of the present invention further comprises a movement control system. In use, the movement control system provides signals to control the operation of the actuation system and control the movement of the one or more support members of the support assembly. In addition, in embodiments in which the base comprises a fixed base assembly and a moveable base assembly able to move relative to the fixed base assembly, the movement control system also controls the movement, such as rotation, of the moveable base assembly by the actuation system.

The movement control system is configured to receive data regarding the movement of the host platform and movement of the object. In use of the system, the movement control system functions to control the actuation system to move the one or more support members and, if appropriate, the moveable base assembly in response to data received regarding movement of the host platform and the object. Depending upon the operation being carried out, the movement control system is configured to operate in a number of modes, as described in more detail below.

The movement control system is configured to receive data relating to the movement of the host platform. A floating platform, such as a vessel or object, in the water has six degrees of freedom of movement, three rotational movements and three linear movements, namely heave, pitch, roll, surge sway and yaw. The movement control system is preferably configured to receive data relating to one or more of the six degrees of freedom of movement, that is the heave, pitch, roll, surge, sway and yaw of the host platform. The movement control system is preferably configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of the host platform.

In the case of the host platform being equipped with a system for detecting motion of the host platform in the water, the movement control system may be configured to receive data from the motion detection system of the host platform. For example, many vessels, such as ships, are equipped with a system for sensing the movement of the vessel on the water as a component of the control systems of the vessel. In such cases, data regarding movement of the host platform can be obtained by the movement control system directly from the system of the host platform. Such data can be transmitted to and received by the movement control system in any suitable manner, for example by a wired connection or by a wireless connection.

In cases where the host platform does not have its own system for detecting motion of the host platform, the system of the present invention may comprise a motion sensing system for detecting motion of the host platform and providing data regarding the movement of the host platform to the movement control system. One preferred system for sensing motion of the host platform comprises an inertial motion unit (IMU) and a global navigation satellite system (GNSS). Suitable motion detection systems are known in the art and are commercially available. Examples of commercially available systems include the CPT7 of Novatel, USA. The use of such systems is preferred, even in cases where the host platform has an onboard motion detection system, as the onboard systems may not provide sufficient accuracy to allow the movement of the distal end of the support assembly to fully compensate for the 6 degree movement of the platform in the water.

The movement control system is further configured to receive data relating to movement of the object. In one embodiment, the movement control system receives data relating to movement of the object from an external system. For example, the object may have its own system for detecting its motion and transmitting data relating to such movement. In the case of remotely operated vehicles (ROVs), it is frequently the case that the ROV has its own motion detection system including on-board sensors for detecting its motion and position in the water. Typically, ROVs are connected to the host vessel by way of an umbilical, through which the host vessel provides essential services to the ROV, such as hydraulic and electrical power, as well as allowing communication between the ROV and the host vessel. In such cases, the movement control system can be configured to receive data relating to the motion of the ROV generated by the onboard systems of the ROV via the host vessel. Alternatively, the host vessel may be provided with a system for detecting the motion of objects, such as remote or autonomous vehicles deployed from the vessel. Again, such a system can be utilised to provide data regarding movement of the object to the movement control system.

In an alternative embodiment, the system of the present invention further comprises a motion tracking system for detecting movement of the object, including allowing the motion of the object to be tracked. The motion tracking system provides the movement control system with data relating to the movement of the object. The motion tracking system operates remotely of the object, for example from the assembly and/or the host platform. Any suitable system for detecting movement of the object may be employed. In one preferred embodiment, the motion tracking system is based on optical sensing of the position of the object. In particular, one preferred system employs one or more, preferably two or more, cameras mounted on the host platform for detecting movement of the object. The object may be provided with suitable markers on its outer surface, such as colour markers, which may be tracked by the one or more cameras. In one preferred embodiment, the motion tracking system comprises one or more pairs of cameras, the cameras in each pair operating in stereo. In one embodiment, the one or more cameras are mounted on the base of the system.

The movement control system is configured to receive data relating to the movement of the object. In particular, the movement control system is preferably configured to receive data relating to one or more of the heave, pitch, roll, surge, sway and yaw of the object. The movement control system is preferably configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of the object. The system providing data to the movement control system is configured to provide data relating to the aforementioned range of motion.

In embodiments in which the host platform is a fixed platform, it may be sufficient for the movement control system to be provided with data relating to the heave, surge and sway of the object, which may allow the movement of the distal end of the support assembly to compensate for relative movement between the object and the host platform, thereby allowing for a proper and safe engagement of the support assembly with the object. In cases where the host platform is a floating platform, for example a vessel, it is preferable that the movement control system is provided with data relating to all of the heave, pitch, roll, surge, sway and yaw of the object, to ensure a safe and efficient engagement of the support assembly with the object.

Data regarding movement of the object received from an onboard detection system of the object will be data regarding the actual movement of the object in the 30 water. In contrast, data regarding movement of the object from a detection system of the host platform may be data relating to movement of the object relative to the host platform. For example, in cases where the system of the present invention comprises a motion tracking system for sensing movement of the object, data received by the movement control system from the motion tracking system will relate to relative movement between the object and the system of the present invention and its host platform. The movement control system may be configured to receive and process both data relating to the actual movement of the object and data relating to relative movement of the object and the host platform.

The movement control system is configured to determine the movement of the object relative to the host platform. This determination is based on the data received regarding movement of the host platform and data received regarding the actual movement of the object or the movement of the object relative to the host vessel. In cases where the host platform is stationary, there is no movement of the host platform to be considered and the actual movement of the object will also be the movement of the object relative to the host platform. In cases where the system comprises a motion tracking system, data generated by the motion tracking system will be data relating to the movement of the object relative to the system and the host platform on which it is mounted.

In one embodiment, the movement control system is further configured to receive data relating to the movement of a platform other than the host platform, for example a floating platform, such as a vessel. In this way, the movement control system can determine the relative movement between the host platform and the other platform, allowing the system to move an object onto or off of the other platform. The movement control system may use data relating to the motion of the other platform provided by a remote system. In many cases, the other platform, such as a vessel, will have its own onboard system for detecting movement of the platform. In such cases, the movement control system can be provided with data relating to movement of the other platform from such onboard systems. The data may be provided to the movement control system by any suitable means. A wireless link between the onboard system of the other platform and the movement control system is particularly suitable. Alternatively, the assembly may be provided with a motion tracking system for sensing the motion of the other platform and allowing the movement of the other platform to be tracked. Any suitable system for sensing movement of the other platform may be employed. In one preferred embodiment, the motion tracking system is based on optical sensing of the position of the object. In particular, one preferred system employs one or more, preferably two or more cameras mounted on the host platform for detecting movement of the other platform. The other platform may be provided with suitable markers on its outer surface, such as colour markers, which may be tracked by the one or more cameras. In one preferred embodiment, the motion tracking system comprises one or more pairs of cameras, the cameras in each pair operating in stereo. In one embodiment, the one or more cameras are mounted on the base of the system.

The movement control system is configured to receive data relating to the movement of the other platform. In particular, the movement control system is preferably configured to receive data relating to one or more of the heave, pitch, roll, surge, sway and yaw of the other platform. The movement control system is preferably configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of the other platform. The system providing data to the movement control system is configured to provide data relating to the aforementioned range of motion.

In embodiments in which the host platform is a fixed platform, it may be sufficient for the movement control system to be provided with data relating to the heave, surge and sway of the other platform, which may allow the movement of the distal end of the support assembly to compensate for relative movement between the other platform and the host platform, thereby allowing for a proper and safe engagement and/or release of an object on the other platform. In cases where the host platform is a floating platform, for example a vessel, it is preferable that the movement control system is provided with data relating to all of the heave, pitch, roll, surge, sway and yaw of the other platform, to ensure a safe and efficient placement or removal of the object on or from the other platform.

In one embodiment, a single motion tracking system is used to sense motion of the object, including tracking its movement, and sensing the movement of the other platform, including tracking its movement, as required for the particular operation being conducted, and provide relevant data to the movement control system.

The movement control system of the system of the present invention is operable in a number of different modes.

In a first mode, the movement control system receives data relating to the movement of the host platform. The movement control system controls movement of the support assembly and, if appropriate, the base, to move the distal end of the support assembly along a path between the first position and the second position that is independent of the movement of the host platform. That is, the movement of the distal end of the support assembly and, hence, any object attached to the distal end, between the first and second positions is not affected by the host platform moving. This mode of operation is herein referred to as the 'space stabilised mode'. As described in more detail hereinafter, this mode of operation is advantageous when deploying a floating object from the host platform.

In a second mode, the movement control system determines the movement of the object relative to the host platform, in particular when the object is out board of the host platform. In embodiments where the movement control system receives data regarding movement of the host platform, such as a system on board the host platform, and data regarding movement of the object, such as a system on board the object, the movement control system makes a determination of the relative movement of the host platform and the object. In embodiments where data relating to the movement of the object relative to the host platform is provided to the movement control system, for example when the system comprises and employs a motion tracking system operating to determine movement of the object from the host platform, the data received by the movement control system relate to relative movement between the host platform and the object. Using the received or determined data relating to the movement of the object relative to the host platform, the movement control system controls movement of the distal end of the support assembly and, if appropriate, the base to move distal end of the support assembly along a path to match the movement of the object. This mode of operation is herein referred to as the 'object synchronised mode'. As described in more detail hereinafter, this mode of operation is particularly advantageous when recovering a floating object from a deployed position to the host platform. In particular, operation in the object synchronised mode allows the distal end of the support assembly to be engaged with the object prior to the support assembly moving the object without any risk of damage to either the object or the support assembly due to a collision between the two occurring.

In a third mode, the movement control system determines the movement of another platform, such as a vessel or floating buoy, relative to the host platform. In embodiments where the movement control system receives data regarding movement of the host platform, such as a system on board the host platform, and data regarding movement of the other platform, such as a system on board the other platform, the movement control system makes a determination of the relative movement of the host platform and the other platform. In embodiments where data relating to the movement of the other platform relative to the host platform is provided to the movement control system, for example when the system comprises and employs a motion tracking system to determine movement of the other platform from the host platform, the data received by the movement control system relate to relative movement between the host platform and the other platform. Using the received or determined data relating to the movement of the object relative to the host platform, the movement control system controls movement of the distal end of the support assembly and, if appropriate, the base to move distal end of the support assembly along a path to match the movement of the object. This mode of operation is herein referred to as the 'platform synchronised mode'. As described in more detail hereinafter, this mode of operation is advantageous when recovering an object from a deployed position to the host platform. In particular, operation in the platform synchronised mode allows the distal end of the support assembly to be engaged with the object prior to the support assembly moving the object on to or off of the other platform. This mode is also advantageous when moving an object onto or off the other platform, for example a vessel floating on the body of water.

In a fourth mode, the movement control system is used merely to control the movement of the support assembly and, if appropriate, the base to move the distal end of the support assembly with the movement of the host platform. In this mode, the path of movement of the distal end of the support assembly is determined by the actions of the movement control system and the movement of the host platform. This mode is herein referred to as the 'unstabilised mode'. This mode is used, for example, to move the distal end of the support assembly into a position where the engagement assembly can be engaged with the object on or in the host platform, for example prior to deploying the object from the host platform.

In a further aspect, the present invention provides a host platform comprising a system as hereinbefore described.

As described hereinbefore, the system of the present invention may be employed to deploy an object from the host platform. In this respect, deploying' is a reference to moving the object from the first position on or within the host platform to a second position at an outboard location, for example into the body of water in close proximity to the host platform, onto or into a floating platform, such as a vessel or buoy, or onto a fixed platform, such as a wind turbine tower or other fixed structure.

When deploying a object from a first position on or in the host platform, the distal end of the support assembly is moved to an engagement position relative to the object, in which the engagement assembly may be releasably engaged with the object. The object is releasably engaged with the distal end of the support assembly. This part of the operation is conducted with the movement control system in the unstabilised mode. In this way, the distal end of the support assembly the engagement assembly moves with the movement of the object on or in the host platform.

With the object releasably engaged with the distal end of the support arm, the support assembly can be moved to move the object from the host platform. Thereafter, once the object is clear of the host platform, the procedure to be followed depends upon the type of host platform and the location of the second position.

In the case of a floating host platform, such as a vessel, the movement control system can be switched to the space stabilised mode. In this mode, the distal end of the support assembly and the object may be moved along a deployment path to the second position. As noted above, in this mode, the deployment path followed by the distal end of the support assembly and the object is independent of the movement of the host platform.

In the case of deploying the object directly into the body of water, the second position is in the water and the object may be released once in the second position and the distal end of the support assembly moved away from the object. The support assembly may then be returned to a stowed position with the movement control system in the unstabilised mode.

The same procedure may be followed to deploy the object from the floating host platform onto a fixed platform.

In the case of deploying an object from a first position on a fixed host platform directly into the water, the movement control system can be kept in the unstabilised mode and the object moved from the first position on the host platform to the second position in the water.

In the case of deploying an object from a first position on the host platform to another platform that is floating, such as a vessel, an alternative procedure is followed. With the movement control system in the unstabilised mode, the distal end of the support assembly is engaged with the object in the first position on the host platform. The support assembly is moved to move the object clear from the host platform.

The movement control system is then switched to the platform synchronised mode and the object moved to the second position on the other platform. During this movement, the movement control system moves the distal end of the support assembly on the basis of data relating to the relative movement of the other platform and the host platform, such that the path followed by the distal end of the support assembly and the object is synchronised to the relative motion of the host platform and the other platform. Once the object is in the second position on the other platform, the distal end of the support assembly is disengaged from the object and the support assembly moved away from the other platform. Once the distal end of the support assembly is clear of the other platform, the movement control system is preferably switched to the space stabilised mode and the support assembly can be manoeuvred to bring the distal end close to the host platform. Once close, the system is switched to the unstabilised mode, in which the support assembly can be returned to a stowed position on the host platform. In cases where the host platform is fixed, the actual movement of the other platform will also be its movement relative to the host platform. The movement control system can operate on the basis of data relating to the motion of the other platform alone. In cases where the host platform is not fixed, operating in the platform synchronised mode requires the movement control system to receive data relating to the actual movement of both the host platform and the other platform, in order to determine their relative motion, or to receive data, for example from the motion sensing system on the host platform, relating to the relative motion of the host platform and the other platform.

A recovery operation is moving the object from the second position to the first position. When recovering an object from a second position in the water or on a platform floating in the water, such as a vessel, to a first position on the host platform, the movement control system operates in the object synchronised mode, in which the movement of the distal end of the support assembly is synchronised with the relative movement of the object and the host platform. The movement control system may be switched to the object synchronised mode during the recovery procedure, once the distal end of the support assembly has been moved and before an attempt is made to connect the engagement assembly with the object. In one embodiment, the movement control system moves the distal end of the support assembly to a recovery position, in which the distal end and the engagement assembly are in close proximity to the object and the object synchronised mode is engaged with the distal end in this position. Wth the system operating in the object synchronised mode, the movement of the distal end of the support assembly and, hence, the engagement assembly is matched or synchronised with the relative movement of the object and the host platform. The distal end of the support assembly is then moved towards the object to allow the engagement assembly to engage with the object. When the object is in the water, once the distal end of the support assembly is engaged with the object, the system is switched to the space stabilised mode. This switch may be made automatically, with the system sensing when the distal end of the support assembly and the object are engaged. Alternatively, this switch may be made manually by an operator. When the object is in or on another platform, such as a vessel, the object is first raised from the other platform after being engaged by the support assembly, after which the system is switched to space stabilised mode. The object is then moved towards the host platform for stowing. Before the object reaches the host platform, io the system is switched to the unstablised mode. As the system is mounted on the host platform, in this mode movement of the distal end of the support assembly and the object attached thereto move with the movement of the host platform. The object can be safely placed in or on the host platform and disengaged from the support assembly.

is When it is required to recover the object from a second position in the water or on a platform floating in the water, such as a vessel, to a first position on a platform other than the host platform, a similar procedure is followed to engage the object.

When moving the object to a second position on a platform that is fixed, once the object is clear of the water or its platform, the movement control system is switched from the object synchronised mode to the space stabilised mode. The object can then be moved along a path independently of movement of the host platform and placed on or in the fixed platform. If the host platform is fixed, the movement control system can be operated in the unstabilised mode.

When moving the object from a first position in the water or on a platform floating in the water, such as a vessel, to a second position on a platform that is floating, such as a vessel, once the object is clear of the water or its platform, the movement control system is switched from the object synchronised mode, in which movement of the distal end is synchronised with movement of the object to the platform synchronised mode. The object can then be moved along a path synchronised with movement of the floating platform to be placed on or in the floating platform.

As discussed above, in a number of scenarios, with the movement control system in the object synchronised mode the distal end of the support system is engaged with the object, in particular to move the object from the second position to the first position. Once the distal end of the support system has been engaged with the object, the movement control system is preferably switched to the space stabilised mode. When the object is in the water, it is preferable that the switch from the object synchronised mode is performed at the same time that the distal end of the support system is engaged with the object or immediately that engagement has been sensed and confirmed. When the object is in or on another platform, it is preferable that the switch from the object synchronised mode is performed after the object has been raised clear of the platform. Switching from the object synchronised mode is preferably performed automatically, without any input from an operator, or semiautomatically, after an operator has switched on the automatic procedure. In one preferred embodiment, the system comprises an engagement detector for sensing proper engagement of the engagement assembly at the distal end of the support system with the object. The movement control system is preferably configured to receive a signal from the engagement detector indicating proper engagement with the object and automatically switches out of the object synchronised mode of operation.

As discussed above, the present invention may be used in a range of different situations to move objects between a first position and a second position. Such situations include: Deploying a remote vehicle, such as an ROV or AUV, into the water from a vessel and recovering the remote vehicle from the water to the vessel; Moving an object between a host vessel or other host floating platform and another vessel or floating platform; Moving an object between the water or a first vessel and a second vessel or fixed platform with the system on a host platform; and Moving an object between a first fixed platform and a second fixed platform.

Embodiments of the present invention will now be described, by way of example only, having reference to the accompanying drawings, in which: Figure 1 is a diagrammatic representation of a system according to one embodiment of the present invention; Figure 2a is an isometric view of a system according to one embodiment of the present invention in a first position; Figure 2b is an isometric view of the system of Figure 2a in a second position; Figure 2c is an isometric view of the system of Figure 2a mounted on the deck of a vessel; Figure 3 is a perspective view of one embodiment of an engagement assembly for use in the system of the present invention; Figure 4 is an isometric view of the system of Figure 2 in a first position during an operation to deploy a floating object from a vessel; Figure 5 is an isometric view of the system of Figure 2 in a second position during an operation to deploy a floating object from a vessel; Figure 6 is an isometric view of the system of Figure 2 in a third position during an operation to deploy a floating object from a vessel; Figure 7 is an isometric view of the system of Figure 2 in a fourth position during an operation to deploy a floating object from a vessel; Figure 8 is an isometric view of the system of Figure 2 in a first position during an operation to recover a floating object to a vessel; Figure 9 is an isometric view of the system of Figure 2 in a second position during an operation to recover a floating object to a vessel; Figure 10 is an isometric view of the system of Figure 2 in a third position during an operation to recover a floating object to a vessel; and Figure 11 is an isometric view of the system of Figure 2 in a fourth position during an operation to recover a floating object to a vessel.

Turning to Figure 1, there is shown a diagrammatical representation of a system according to one embodiment of the present invention. The system, generally indicated as 2, comprises an assembly 4 having a base 6 and a support assembly 8. The assembly 4 is represented in Figure 1 as being mounted on a floating vessel 10 serving as a host platform.

The system 2 further comprises a movement control system 20. The movement control system 20 controls movement of the support assembly 8 and the base 6 by way of control signals sent to an actuation system of the assembly 4 via a signal line 22. The movement control system 20 is configured to receive data relating to motion of the vessel 10, indicated in Figure 1 as data signals being received from the onboard system of the vessel 10 via a signal line 24. The movement control system 20 is further configured to receive data relating to the motion of a floating object 26. In the arrangement shown in Figure 1, the movement control system 20 receives data directly from the floating object 26 by way of a signal line 28, for example when the floating object 26 is a remotely operated vehicle (ROV), an umbilical extending from the ROV. Alternatively, or in addition, the movement control system 20 is configured to receive via a signal line 30 data from a motion detecting system mounted on the base 6 of the assembly and configured to sense the motion of the floating object 26. In addition, the movement control system 20 is configured to receive data relating to the movement of another platform, in particular a vessel 32 having an onboard motion sensing system. Data from the vessel 32 is transmitted to the movement control system 20 by way of a signal line 34, which may be a wireless connection.

In use of the system 2, a floating object 26, such as an ROV, may be deployed from a first position on the host vessel 10 to a second position in the water, as shown in Figure 1, and recovered from the second position in the water to the first position on the host vessel 10. Alternatively, the floating object 26 may be moved between a first position on the host vessel 10 and a second position on the vessel 32. In a further alternative, the system 2 may be used from the host vessel 10 to move the floating object 26 between a position on the vessel 32 and a position in the water.

Turning to Figures 2a and 2b, there are shown two isometric views of an assembly according to one embodiment of the present invention, generally indicated as 102. The assembly 102 is shown in a stowed position in Figure 2a and in a deployed position in Figure 2b.

The assembly 102 comprises a base 110 and a support assembly 130. The base assembly 110 has a fixed base assembly 112 comprising three legs 114 extending radially outwards from a central fixed base member 116. A moveable base assembly 118 is rotatably mounted on the fixed base member 116 and comprises a rotatable base member 120. Having the moveable base assembly 118 rotatable is about the fixed base member 116 allows for compensation of movement of the host platform, including yaw movements.

The support assembly 130 has a proximal end 132 and a distal end 134. The support assembly 130 comprises four elongate support members, as follows: The support assembly 130 comprises a first support member 140 extending from the proximal end 132 of the support assembly and pivotally mounted at a first end to the rotatable base assembly 118. The pivot connection between the first support member 140 and the rotatable base assembly 118 allows for compensation of the pitch and roll of the host platform.

A second support member 142 is pivotally mounted at a first end to a second end of the first support member 140.

A third support member 144 is pivotally mounted at a first end to a second end of the second support member 142.

A fourth support member 146 is pivotally mounted at a first end to the second end of the third support member 144 and has a second end forming the distal end 134 of the support assembly 130.

The system 2 further comprises a motion tracking system 150, shown in Figure 2c comprising a pair of cameras 152 mounted on a lateral spar 154, in turn mounted on a leg 114 of the fixed base assembly 112. Image data from the cameras is processed by a remotely mounted computer (not shown for clarity), which also forms part of the motion tracking system 150. In use, the motion tracking system 150 is used to detect and track motion of a floating object and/or the motion of another 1.0 platform or vessel. Data from the motion tracking system 150 is provided to the movement control system 20, as described hereinbefore.

The system 2 further comprises an actuation system 160, which operates to move the components of the support assembly 130 and the base 110. The actuation system 160 shown in Figures 2a to 2c is a hydraulic system, by way of example. The is actuation system comprises a first hydraulic ram 162 extending from a leg 114 of the fixed base assembly 112 to the rotatable base member 120. A pair of second hydraulic rams 164 extend from the rotatable base member 120 on either side of the first support member 140 to a position on the first support member 140. A third hydraulic ram 166a extends between the first support member 140 and the second support member 142. A fourth hydraulic ram 166b extends from the second support member 142 to the third support member 144. A fifth hydraulic support member 166c extends from the third support member 144 to the first end of the fourth support member 146 adjacent its pivot connection with the third support member 144.

An engagement assembly 170 is provided on the second end of the fourth support member 146 at the distal end 134 of the support assembly. Further details of the engagement assembly 170 are shown in Figure 3 and described in more detail below.

The movement control system 20 is shown in Figures 2a and 2b mounted to a leg 114 of the fixed base assembly 112.

A floating object 26, in the form of a Remote Operated Vehicle (ROV) is shown in a first position on the deck 104 in Figure 2c.

Turning to Figure 3, there is shown a perspective view of the engagement assembly 170 provided at the distal end 134 of the support assembly 130 of Figure 2.

The engagement assembly 170 is the female part of a male-female engagement system and comprises a generally cylindrical body 172 having a mounting flange 174 disposed at one end for mounting to the end of the fourth support member 146. The body 172 has a receiving cavity 176 at its other end, from which extends a frustoconical guide member 178. A plurality of locking fingers 180 are spaced around the to opening of the receiving cavity 176 and extend radially inwards. The locking fingers are each retractable under the action of a respective solenoid 182 acting through a biasing spring 184. The spring 184 biases the respective locking finger 180 into a locking position.

A male engagement assembly 190 comprises a generally circular flange 192, is from which extends an elongate engaging member 194 having a spherical cap 196 at its free end. A circumferential groove 198 extends around the engagement member 194 adjacent the flat surface of the spherical cap 196.

As can be seen in Figure 2c, the male engagement assembly 190 is mounted to the upper surface of the floating object 26, that is the ROV.

In use, the engagement assembly 170 is manoeuvred over the male engagement assembly 190 and lowered onto the male engagement assembly until the spherical cap 196 is received in the receiving cavity 176. The locking fingers 180 engage with the groove 198 in the engaging member 194. To disengage the assembly, the solenoids 182 are activated to withdraw the locking fingers 180 from engagement with the groove 198, allowing the engagement assembly 170 to be withdrawn from the male engagement assembly 190.

Turning to Figures 4 to 7, there is shown a sequence of operations for deploying the ROV 26 from the deck 104 of the vessel 106 into the water. Figures 4 to 7 show isometric views of an assembly 102. The assembly 102 is shown mounted on the deck 104 of a ship 106.

In a first step, shown in Figure 4, with the movement control system 20 in the unstabilised mode, the assembly 102 is moved into a position with the engagement assembly 170 at the distal end 134 over the ROV 26. The assembly 102 is lowered, to engage the engagement assembly 170 with the male engagement assembly 190 on the ROV 26. Thereafter, the assembly 102 is operated to raise the ROV 26 from the first position on the deck 104 of the vessel 106 and is rotated to move the ROV outwards over the water, as shown in Figure 5.

The movement control system 20 is switched to the space stabilised mode, in which the movement control system 20 moves the ROV along a path that is independent of the movement of the vessel 106. With the movement control system 20 in this mode, the ROV 26 is lowered into position in the water, as shown in Figure 6. The assembly 102 is then disengaged from the ROV 26 and the distal end 134 is raised clear of the ROV in the water, as shown in Figure 7. From this position, the movement control system 20 is switched to the unstabilised mode and the support assembly may be returned to a stowed condition.

Turning to Figures 8 to 11, there is shown a sequence of operations for receiving the ROV 26 from the water to the deck 104 of the vessel 106. Figures 8 to 11 show isometric views of an assembly 102. The assembly 102 is shown mounted on the deck 104 of a ship 106.

In a first step, shown in Figure 8, with the movement control system 20 in the object synchronised mode, the support assembly is moved into a position with the engagement assembly 170 at the distal end 134 over the ROV 26. The assembly 102 can be moved automatically using the movement control system in an auto-locate mode, using data received from the motion tracking system 150. With the movement control system 20 in the object synchronised mode, movement of the distal end 134 and the engagement assembly 170 is synchronised to match the movement of the ROV 26 in the water. The motion tracking system 150 senses movement of the of the ROV, in particular by the cameras 152 capturing images of markers 200 on the upper portion of the ROV and providing data to the movement control system 20. When ready, the assembly 102 is lowered, to engage the engagement assembly 170 with the engagement member 190 on the ROV 26, as shown in Figure 9. The movement control system is configured to perform this operation automatically. Just as the assembly 102 engages with the ROV 26, the movement control system is automatically switched to the space stabilised mode.

Thereafter, the movement control system 20 raises the support assembly 130 and lifts the ROV 26 from the water, as shown in Figure 10. At the same time the movement control system 20 is switched to the unstabilised mode, after which the ROV 26 can be lowered into the first position on the deck 104 of the vessel 106. The support assembly 102 is then disengaged from the ROV 26 and the distal end 134 raised clear of the ROV, as shown in Figure 11. From this position, the movement control system 20 the support assembly may be returned to a stowed condition.

Claims

CLAIMS1. A system for moving an object from a first position to a second position, wherein the system is configured to be mounted on a host platform located in, on or adjacent a body of water, the system comprising: an assembly for supporting and moving an object, the assembly comprising: a base for mounting on a host platform; a support assembly having a proximal end mounted on the base and a distal end for connecting to the object, the distal end of the support assembly being moveable relative to the base between a position in which the distal end of the support assembly is engageable with the object in the first position and a position in which the distal end of the support assembly is engageable with the object in the second position, the distal end of the support assembly comprising an engagement assembly for releasably engaging the support assembly with the object; and an actuation system for moving the distal end of the support assembly; the system further comprising: a movement control system configured to receive data regarding movement of the host platform and data regarding the motion of the object when the object is moving independently of the host platform, the movement control system further configured to provide control signals to the actuation system for moving the distal end of the support assembly, the movement control system controlling the distal end of the support assembly to move along a path between the first position and the second position independently of the movement of the host platform or synchronised with the movement of the object when the object is moving independently of the host platform.
The system according to claim 1, wherein the base comprises a fixed base assembly for securing to the host platform and a moveable base assembly mounted to the fixed base assembly for movement relative to the fixed base assembly, the support assembly being mounted on the moveable base assembly.
3. The system according to claim 2, wherein the moveable base assembly is rotatable relative to the fixed base assembly.
4. The system according to any preceding claim, wherein the support assembly comprises an articulated assembly comprising a plurality of support members.
5. The system according to claim 4, wherein the support assembly comprises an articulated assembly comprising a first support member pivotally mounted to the base and extending in the distal direction, a second support member pivotally connected to the end of the first support member and extending distally, a third support member pivotally connected to the end of the second support member and extending distally, and a fourth support member pivotally connected to the end of the third member and extending to the distal end of the support assembly.
6. The system according to any preceding claim, wherein the base and the support assembly are configured to allow the distal end of the support assembly to have a freedom of movement that allows the movement of the distal end to compensate for movement of the host platform in six degrees, namely heave, pitch, roll, yaw, surge and sway.
The system according to any preceding claim, wherein the movement control system is configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of the host platform.
The system according to any preceding claim, further comprising a motion sensing system for sensing motion of the host platform and providing data regarding the movement of the host platform to the movement control system.
9. The system according to any preceding claim, further comprising a motion tracking system for tracking movement of the object, preferably an optical sensing system comprising two or more cameras.
10. The system according to any preceding claim, wherein the movement control system is configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of the object.
11. The system according to any preceding claim, further comprising a motion tracking system for tracking movement of a platform other than the host platform, preferably an optical sensing system comprising two or more cameras.
12. The system according to any preceding claim, wherein the movement control system is configured to receive data relating to two or more, more preferably three or more, still more preferably four or more, more preferably still five or more, especially all of heave, pitch, roll, surge, sway and yaw of a platform other than the host platform.
13. The system according to any preceding claim, wherein the movement control system is configured to control movement of the support assembly in an unstabilised mode, a space stabilised mode, an object synchronised mode and/or a platform synchronised mode.
14. A host platform comprising a system as hereinbefore described.
15. The host platform according to claim 14, wherein the platform is a fixed platform or a floating platform.
16. A method for deploying an object from a first position to a second position, the method comprising: providing a support assembly on a host platform, the support assembly having a proximal end mounted to the host platform and a distal end, the distal end of the support assembly being moveable relative to the host platform; releasably engaging the distal end of the support assembly with the object; moving the distal end of the support assembly from the first position to the second position, whereby the object is moved along a path independent of movement of the host platform; and releasing the engagement between the distal end of the support assembly with the object at the second position.
17. A method for recovering an object from a second position to a first position, the method comprising: providing a support assembly on a host platform, the support assembly having a proximal end mounted to the host platform and a distal end, the distal end of the support assembly being moveable relative to the host platform; synchronising the movement of the distal end of the support assembly with the movement of the object in response to data received regarding the relative movement of the host platform and the object; engaging the distal end of the support assembly with the object; and moving the object from the second position to the first position. 18. 19. 20. 21. 22. 23.
The method according to either of claims 16 or 17, wherein the object is a floating object.
The method according to claim 18, wherein the object is a remotely operated vehicle (ROV) or an autonomous underwater vehicle (AUV).
The method according to any of claims 16 to 19, wherein the host platform is a floating platform, preferably a vessel, or wherein the host platform is a fixed platform, preferably an offshore wind turbine tower secured to the seabed.
The method according to any of claims 16 to 20, wherein the first position is on the host platform or wherein the first position on a platform other than the host platform.
The method according to claim 21, wherein the platform other than the host platform is a fixed platform or is a floating platform, preferably a vessel.
The method according to any of claims 16 to 22, wherein the second position is in a body of water adjacent the host platform.
24. The method according to any of claims 16 to 22, wherein the second position is in or on a platform other than the host platform.
25. The method according to claim 24, wherein the platform other than the host platform is a fixed platform or is a floating platform, preferably a vessel.