Connecting System and Method for Connecting an Unmanned Underwater Vehicle to a Floating Vehicle

This application is a national stage application of PCT/IB2023/055344, filed on May 24, 2023, which claims the benefit of and priority to Italian Patent Application No. 102022000011060, filed on May 26, 2022, the entire contents of which are each incorporated by reference herein.

The present disclosure relates to a connecting system and to a connecting method for connecting an unmanned underwater vehicle to a vehicle floating in a body of water.

Unmanned underwater vehicles of an autonomous unmanned vehicle (“AUV”) type at a work site are employed for carrying out underwater operations such as, for example, operations for the inspection of underwater hydrocarbon production installations or the monitoring of underwater structures.

Generally, these AUVs are assisted on the surface by a floating support vehicle, which is configured to launch, control and retrieve on board the AUV.

As they are not connected to external power sources, these AUVs have a relatively limited autonomy in terms of time of use, space that can be covered with a single charge and exertable force.

These relative limits in autonomy do not allow, for example, known AUVs to navigate from an underwater work site to a further underwater work site in cases where the distance between these work sites is greater than the maximum distance the AUV can travel with a single charge.

Consequently, to transfer AUVs from one underwater work site to a further underwater work site, it is necessary to retrieve the AUV on board the floating support vehicle, to transport the AUV on board the floating support vehicle, and to launch the AUV again at the further underwater work site.

Moreover, when the AUV needs to be recharged due to the depletion of power reserves, the AUV to be recharged is typically retrieved on board the floating support vehicle or, alternatively, the AUV is retrieved in an underwater housing station connected to the floating support vehicle via an umbilical. However, to launch and retrieve the AUV and/or the underwater housing station, it is necessary for the floating vehicle to be equipped with a launch and retrieval system. The launch and retrieval systems are typically relatively bulky, require relatively significant installation/removal times and costs for their installation/removal on board the floating vehicle and occupy a relatively large amount of space on the floating vehicle, which must be specifically designed as a function of the use of the launch and retrieval system.

Moreover, the launch and the retrieval of an AUV by certain launch and retrieval systems require a relatively large amount of time and can only be carried out in relatively favorable meteorological and environmental conditions.

In various embodiments, an object of the present disclosure is to provide a connecting system for connecting an unmanned underwater vehicle to a floating vehicle in a body of water that is able to overcome certain of the drawbacks of certain of the prior art. In particular, an object of the present disclosure is to enable the transport, the recharging and the data exchange of the unmanned underwater vehicle in a relatively simple and risk-free manner, while keeping the unmanned underwater vehicle in the body of water.

According to certain embodiments of the present disclosure, a connecting system for connecting an unmanned underwater vehicle to a floating vehicle in a body of water is provided, the connecting system including a connecting device configured to be connected mechanically and/or electrically and/or for data exchange to the unmanned underwater vehicle in the body of water; and an articulated arm, which is configured to be mounted to the floating vehicle and is connected to the connecting device so as to control the position and the orientation of the connecting device in the body of water.

According to certain embodiments of the present disclosure, it is possible to connect the unmanned underwater vehicle to the floating vehicle to enable the recharging of the unmanned underwater vehicle and the transport of the unmanned underwater vehicle from a work site to a further work site without the need to retrieve the unmanned underwater vehicle on board the floating vehicle. In other words, it is possible to keep the unmanned underwater vehicle in the body of water during the steps of transporting and/or of recharging the unmanned underwater vehicle. It is thus not necessary for the floating vehicle to be equipped with a relatively bulky launch and retrieval system to launch and retrieve the unmanned underwater vehicle and, as a result, it is possible for the floating vehicle to have relatively reduced dimensions or for the space dedicated to the launch and retrieval system to be used for other purposes.

Moreover, since it is not necessary to employ a launch and retrieval system, it is possible to transport and/or recharge the unmanned underwater vehicle in a relatively short amount of time and even in relatively adverse meteorological and environmental conditions, which increases the operational window of the connecting system. In particular, the articulated arm comprises an actuation assembly configured to control the position and the orientation of the connecting device with respect to the unmanned underwater vehicle. It is thus possible to connect the connecting device to the unmanned underwater vehicle by moving the connecting device in the body of water towards the unmanned underwater vehicle, while the relative position of the unmanned underwater vehicle with respect to the floating vehicle is kept substantially unchanged.

It should be appreciated that the relatively low mass and relatively high maneuverability of the articulated arm enable the connecting device to be moved in the body of water relatively precisely and quickly and simplify the docking of the unmanned underwater vehicle. In practice, during connecting operations, the articulated arm moves a relatively small mass of water, which increases the inertia of the articulated arm in the body of water to a limited extent. In particular, the articulated arm comprises a support element configured to be solidly coupled to the floating vehicle; a first elongated element, which extends along a first longitudinal axis and is hinged to the support element about a first rotation axis; a second elongated element, which extends along a second longitudinal axis, is hinged to the first elongated element about a second rotation axis and carries the connecting device. In certain embodiments, the first rotation axis is transverse to the second rotation axis.

It should be further appreciated that based on the first elongated element being hinged to the support element about a first rotation axis and the second elongated element being hinged to the first elongated element about a second rotation axis, the articulated arm has two degrees of freedom with respect to the floating vehicle. This way, the articulated arm enables the connecting device to achieve a plurality of different positions in the body of water.

In particular, the actuation assembly comprises a first actuator configured to control the rotation of the first elongated element about the first rotation axis; and a second actuator configured to control the rotation of the second elongated element about the second rotation axis. This enables relatively easy and precise control of the position of the connecting device in the body of water.

In particular, the first elongated element comprises a first body and a second body hinged to each other about a third rotation axis substantially parallel to the second rotation axis. This way, it is possible to provide the articulated arm with a further degree of freedom so that the articulated arm has three degrees of freedom with respect to the floating vehicle. In this configuration, it is possible to arrange the connecting device close to the surface of the body of water or partially above the surface of the body of water to enable the connection with the unmanned underwater vehicle in that position.

In particular, the actuation assembly comprises a third actuator configured to control the relative rotation of the second body with respect to the first body about the third rotation axis in a relatively simple and precise manner.

In particular, the articulated arm comprises a connecting joint for connecting an end of the second elongated element to the connecting device.

The connecting joint is configured to enable the relative rotation of the connecting device about a fourth rotation axis and about a fifth rotation axis.

The connecting joint gives the connecting device two degrees of freedom with respect to the articulated arm. This enables the connecting device to be oriented in the body of water in a plurality of different directions.

In particular, the first elongated element extends along the first longitudinal axis for a first length greater than the metacentric roll height of the floating vehicle on which the articulated arm is mounted. Metacentric roll height is understood as the distance between the roll metacentre of a floating body and its center of gravity. This makes it possible to achieve a dynamic response at the end of the first elongated element hinged to the second elongated element that is faster than the roll movements of the floating vehicle.

In particular, the second elongated element extends along the second longitudinal axis for a second length greater than the metacentric pitching height of the floating vehicle on which the articulated arm is mounted. Metacentric pitching height is understood as the distance between the pitching metacentre of a floating body and its center of gravity. Such a configuration makes it possible to achieve a dynamic response at the end of the second elongated element connected to the connecting device that is faster than the pitching movements of the floating vehicle.

In particular, the connecting device comprises a plate. This makes it possible to reduce the mass of the connecting device and to increase its manoeuvrability.

In particular, the connecting device comprises at least one mechanical connector configured to releasably engage the unmanned underwater vehicle. Such a configuration makes it possible to keep the unmanned underwater vehicle solidly connected to the connecting device during the transfer of the unmanned underwater vehicle from a work site to a further work site. Moreover, the mechanical connector enables the connecting device to be selectively engaged/disengaged by the unmanned underwater vehicle.

In particular, the connecting device comprises an inductive connector configured to be connected electrically and/or for data exchange to the unmanned underwater vehicle.

When the unmanned underwater vehicle is connected to the inductive connector, it is thus possible to recharge the unmanned underwater vehicle with electric power and simultaneously communicate via cable with the unmanned underwater vehicle.

In particular, the connecting system comprises a control unit configured to control the actuation assembly so as to arrange the connecting device at the unmanned underwater vehicle and to orient the connecting device towards the unmanned underwater vehicle. This enables the position and the orientation of the connecting device in the body of water to be controlled automatically or by an operator.

More specifically, the connecting device comprises at least one sensor configured to detect the relative position between the unmanned underwater vehicle and the connecting device. In certain instances, the at least one sensor is of an optical or acoustic type. The control unit is configured to control the actuation assembly as a function of the detected relative position. This enables the position of the connecting device to be controlled in a closed loop via the feedback of the relative position detected by the at least one sensor.

In various embodiments, a further object of the present disclosure is to provide a navigation assembly that is not subject to certain of the drawbacks of certain of the known art.

According to certain embodiments of the present disclosure, a navigation assembly is provided that includes a floating vehicle configured to navigate on a body of water, an unmanned underwater vehicle configured to navigate in the body of water, and a connecting system as described in the foregoing, which is mounted to the floating vehicle and is configured to connect the floating vehicle to the unmanned underwater vehicle.

By the navigation assembly, it is possible to recharge and transfer the unmanned underwater vehicle from a work site to a further work site, while keeping the unmanned underwater vehicle in the body of water during the steps of transporting and/or of recharging the unmanned underwater vehicle.

According to one embodiment, the floating vehicle is an autonomous unmanned vehicle and the unmanned underwater vehicle is of an AUV type.

In certain embodiments, a further object of the present disclosure is to provide a connecting system for connecting an unmanned underwater vehicle to a floating vehicle in a body of water that is not subject to certain of the drawbacks of certain of the prior art.

According to certain embodiments of the present disclosure, a connecting method for connecting an unmanned underwater vehicle to a floating vehicle in a body of water is provided, the method includes carrying an articulated arm equipped with a connecting device into a body of water by the floating vehicle, controlling the position and the orientation of the connecting device in the body of water by the articulated arm, and connecting mechanically and/or electrically and/or for data exchange the connecting device to the unmanned underwater vehicle.

The present method enables the floating vehicle to be connected to the underwater vehicle relatively quickly and easily. It is thus possible to recharge and/or transport the unmanned underwater vehicle without the need to retrieve the unmanned vehicle on board the floating vehicle.

With reference to, the reference numberindicates, as a whole, a navigation assembly employed in a body of water.

The navigation assemblycomprises a floating vehicleconfigured to navigate on the body of water; an unmanned underwater vehicleconfigured to navigate in the body of water; and a connecting system, which is mounted to the floating vehicleand is configured to connect the floating vehicleto the underwater vehiclein the body of water.

The floating vehiclecan be any type of manned or unmanned vessel configured to navigate on a body of water. In the particular case described and illustrated, which does not limit the present disclosure, the floating vehicleis an autonomous unmanned vehicle (“AUV”). Moreover, in the particular case described and illustrated, the underwater vehicleis of an autonomous unmanned vehicle type.

According to a further embodiment (not shown in the drawings), the underwater vehicleis of a remotely operated vehicle (“ROV”) type.

With reference to, the connecting systemcomprises a connecting deviceconfigured to be connected mechanically and/or electrically and/or for a data exchange to the underwater vehiclein the body of water; and an articulated arm, which is configured to be mounted to the floating vehicle, and which is connected to the connecting deviceso as to control the position and the orientation of the connecting devicein the body of water.

The articulated armcomprises an actuation assemblyconfigured to control the position and the orientation of the connecting devicewith respect to the unmanned underwater vehicle.

In particular, the articulated armcomprises a support elementconfigured to be solidly coupled to the floating vehicle; an elongated element, which extends along a first longitudinal axis Aand is hinged to the support elementabout a rotation axis R; an elongated element, which extends along a longitudinal axis A, is hinged to the elongated elementabout a rotation axis Rand carries the connecting device.

According to certain embodiments, the rotation axis Ris transverse to the rotation axis R. In certain such embodiments, the rotation axis Rand the rotation axis Rare substantially perpendicular to each other.

More specifically, the elongated elementis hinged to the support elementby an endand is hinged to the elongated elementby an endopposite the end.

The elongated elementis hinged to the elongated elementat an endand carries the connecting deviceat an endopposite the end.

In particular, the support elementis configured to be fixed to a gunwale of the floating vehicleso as to protrude in a cantilevered manner from said gunwale towards the body of water().

According to a non-limiting embodiment of the present disclosure, the elongated elementcomprises a bodyand a bodyhinged to each other about a rotation axis Rsubstantially parallel to the rotation axis R.

According to an alternative embodiment (not shown in the drawings), the elongated elementcan be formed by a single elongated body extending along the longitudinal axis A. In particular, the elongated elementextends along the longitudinal axis Afor a length Lgreater than the metacentric roll height of the floating vehicleon which the articulated armis mounted.

Analogously, in certain embodiments, the elongated elementextends along the longitudinal axis Afor a length Lgreater than the metacentric pitching height of the floating vehicleon which the articulated armis mounted. In particular, the actuator assemblycomprises an actuatorconfigured to control the rotation of the elongated elementabout the rotation axis R(); and an actuatorconfigured to control the rotation of the elongated elementabout the rotation axis R. More specifically, the actuatoris configured to act between the support elementand the elongated element. The actuatoris configured to act between the elongated elementand the elongated element.