UNDERWATER VEHICLE TO A FLOATING VEHICLE"

CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Appl ication claims priority from Italian Patent Application No . 102022000011060 filed on May 26 , 2022 , the entire disclosure of which is incorporated herein by reference .

TECHNICAL FIELD

The present invention 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 .

BACKGROUND

It is currently known to employ unmanned underwater vehicles of an AUV ( autonomous unmanned vehicle ) type at a work site 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 limited autonomy in terms of time of use , space that can be covered with a s ingle charge and exertable force .

These 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, in order to trans fer 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, it is retrieved in an underwater housing station connected to the floating support vehicle via an umbilical .

However, in order 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 . Said launch and retrieval systems are typically bulky, require signi ficant installation/removal times and costs for their installation/removal on board the floating vehicle and occupy a large amount of space on the floating vehicle , which must be speci fically designed as a function of the use of said launch and retrieval system .

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

Summary

An obj ect of the present invention 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 the drawbacks of the prior art .

In particular, the obj ect of the present invention is to allow the transport , the recharging and the data exchange of the unmanned underwater vehicle in a simple and risk- free manner, while keeping the unmanned underwater vehicle in the body of water .

According to the present invention, a connecting system for connecting an unmanned underwater vehicle to a floating vehicle in a body of water is provided, the connecting system comprising : 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 .

By means of the present invention, it is possible to connect the unmanned underwater vehicle to the floating vehicle in order to allow the recharging of the unmanned underwater vehicle and the transport of the unmanned underwater vehicle from a work s ite 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 bulky launch and retrieval system in order to launch and retrieve the unmanned underwater vehicle and, as a result , it is possible for the floating vehicle to have 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 short amount of time and even in 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 .

The low mass and high manoeuvrability of the articulated arm allow the connecting device to be moved in the body of water precisely and quickly and simpli fy the docking of the unmanned underwater vehicle . In practice , during connecting operations , the articulated arm moves a 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 ; preferably the first rotation axis being transverse to the second rotation axis .

Due to the fact that the first elongated element is hinged to the support element about a first rotation axis and the second elongated element is 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 allows the connecting device to achieve a plurality of di fferent 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 allows an 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 it 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 in order to allow 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 simple and precise manner .

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

The connecting j oint is configured to allow the relative rotation of the connecting device about a fourth rotation axis and about a fi fth rotation axis .

The connecting j oint gives the connecting device two degrees of freedom with respect to the articulated arm . This allows the connecting device to be oriented in the body of water in a plurality of di f ferent directions .

In particular, the first elongated element extends along the first longitudinal axis for a first length greater than the metacentric roll height o f the floating vehicle on which the articulated arm is mounted .

Metacentric roll height is understood as the distance between the roll metacentre of a f loating body and its centre 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 centre of gravity .

This 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 .

This makes it possible to keep the unmanned underwater vehicle solidly connected to the connecting device during the trans fer of the unmanned underwater vehicle from a work site to a further work site . Moreover, the mechanical connector allows 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 allows the position and the orientation o f the connecting device in the body of water to be controlled automatically or by an operator .

More speci fically, the connecting device comprises at least one sensor configured to detect the relative position between the unmanned underwater vehicle and the connecting device , preferably the at least one sensor being of an optical or acoustic type ; the control unit being configured to control the actuation assembly as a function of the detected relative position .

This allows 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 .

A further obj ect of the present invention is to provide a navigation assembly that is not subj ect to the drawbacks of the known art .

According to the present invention, a navigation assembly is provided that comprises :

- 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 means of the navigation assembly, it is possible to recharge and trans fer 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 .

A further obj ect of the present invention is to provide a connecting system for connecting an unmanned underwater vehicle to a floating vehicle in a body of water that is not subj ect to the drawbacks of the prior art .

According to the present invention, a connecting method for connecting an unmanned underwater vehicle to a floating vehicle in a body of water is provided, the method comprising the steps of :

- carrying an articulated arm equipped with a connecting device into a body of water by means of the floating vehicle ;

- controlling the position and the orientation of the connecting device in the body of water by means of 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 allows the floating vehicle to be connected to the underwater vehicle 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 .

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will become apparent from the following description of a preferred embodiment , with reference to the figures of the attached drawings , wherein : - Figure 1 is a side elevation view, with parts removed for clarity, of a navigation assembly provided in accordance with the present invention;

- Figure 2 is a front view, with parts removed for clarity, of the navigation assembly of Figure 1 ;

- Figure 3 is an enlarged view, with parts removed for clarity, of a detail of the navigation assembly of Figure 1 ;

- Figure 4 is a front view, with parts removed for clarity, of a detail of the navigation assembly of Figure 1 ; and

- Figures 5 and 6 are side elevation views , with parts removed for clarity, of the navigation assembly of Figure 1 in respective operating configurations .

DESCRIPTION OF EMBODIMENTS

With reference to Figure 1 , the reference number 1 indicates , as a whole , a navigation assembly employed in a body of water 2 .

The navigation assembly 1 comprises a floating vehicle 3 configured to navigate on the body of water 2 ; an unmanned underwater vehicle 4 configured to navigate in the body of water 2 ; and a connecting system 5 , which is mounted to the floating vehicle 3 and is configured to connect the floating vehicle 3 to the underwater vehicle 4 in the body of water 2 .

The floating vehicle 3 can be any type of manned or unmanned vessel configured to navigate on a body of water . In the particular case described and illustrated here , which does not limit the present invention, the floating vehicle 3 is an autonomous unmanned vehicle .

Moreover, in the particular case described and illustrated here , the underwater vehicle 4 is of an AUV ( autonomous unmanned vehicle ) type .

According to a further embodiment , not shown in the attached figures , the underwater vehicle 4 is of a ROV ( remotely operated vehicle ) type .

With reference to Figures 1 and 2 , the connecting system 5 comprises a connecting device 6 configured to be connected mechanically and/or electrically and/or for a data exchange to the underwater vehicle 4 in the body of water 2 ; and an articulated arm 7 , which is configured to be mounted to the floating vehicle 3 , and which is connected to the connecting device 6 so as to control the position and the orientation of the connecting device 6 in the body of water 2 .

The articulated arm 7 comprises an actuation assembly 8 configured to control the position and the orientation of the connecting device 6 with respect to the unmanned underwater vehicle 4 .

In particular, the articulated arm 7 comprises a support element 9 configured to be solidly coupled to the floating vehicle 3 ; an elongated element 10 , which extends along a first longitudinal axis Al and is hinged to the support element 9 about a rotation axis R1 ; an elongated element 11 , which extends along a longitudinal axis A2 , is hinged to the elongated element 10 about a rotation axis R2 and carries the connecting device 6 .

According to one embodiment , the rotation axis R1 is transverse to the rotation axis R2 ; preferably the rotation axis R1 and the rotation axis R2 are substantially perpendicular to each other .

More speci fically, the elongated element 10 is hinged to the support element 9 by an end 12 and is hinged to the elongated element 11 by an end 13 opposite the end 12 .

The elongated element 11 is hinged to the elongated element 10 at an end 14 and carries the connecting device 6 at an end 15 opposite the end 14 .

In particular, the support element 9 is configured to be fixed to a gunwale of the floating vehicle 3 so as to protrude in a cantilevered manner from said gunwale towards the body of water 2 ( Figure 2 ) .

According to a non-limiting embodiment of the present invention, the elongated element 10 comprises a body 16 and a body 17 hinged to each other about a rotation axis R3 substantially parallel to the rotation axis R2 .

According to an alternative embodiment , not shown in the attached figures , the elongated element 10 can be formed by a single elongated body extending along the longitudinal axis Al .

In particular, the elongated element 10 extends along the longitudinal axis Al for a length LI greater than the metacentric roll height of the floating vehicle 3 on which the articulated arm 7 is mounted .

Analogously, the elongated element 11 extends along the longitudinal axis A2 for a length L2 greater than the metacentric pitching height of the floating vehicle 3 on which the articulated arm 7 is mounted .

In particular, the actuator assembly 8 comprises an actuator 18 configured to control the rotation of the elongated element 10 about the rotation axis R1 ( Figure 2 ) ; and an actuator 19 configured to control the rotation of the elongated element 11 about the rotation axis R2 .

More speci fically, the actuator 18 is configured to act between the support element 9 and the elongated element 10 . The actuator 19 is configured to act between the elongated element 10 and the elongated element 11 .

Moreover, the actuation assembly 8 comprises an actuator 20 configured to control the relative rotation of the body 17 with respect to the body 16 about the rotation axis R3 .

According to a non-limiting embodiment of the present invention, each actuator 18 , 19 and 20 comprises a hydraulic cylinder .

With reference to Figure 3 , the articulated arm 7 comprises a connecting j oint 21 for connecting the end 15 of the elongated element 11 to the connecting device 6 .

More speci fically, the connecting j oint 21 is configured to allow the relative rotation of the connecting device 6 about a rotation axis R4 and about a rotation axis R5 ; preferably the rotation axes R4 and R5 are substantially perpendicular to each other .

The actuation assembly 8 comprises further actuators , not shown in the attached figures , configured to control the rotation of the connecting device 6 about the rotation axis R4 and the rotation axis R5 .

With reference to Figure 4 , the connecting device 6 comprises a plate 22 .

According to the present invention, the connecting device 6 comprises two mechanical connectors 23 configured to releasably engage the underwater vehicle 4 . Each mechanical connector 23 is arranged on the plate 22 and comprises a quick-release coupling, not shown in the attached figures .

It is understood that the number and arrangement of the mechanical connectors 23 is purely illustrative and is not to be understood as limiting the present invention .

Moreover, the connecting device 6 comprises an inductive connector 24 , which is coupled to the plate 22 and is configured to be connected electrically and/or for data exchange to the underwater vehicle 4 .

According to variants of the present invention, not shown in the accompanying figures , the connecting device 6 comprises a plurality of inductive connectors 24 .

The connecting device 6 comprises at least one sensor 25 configured to detect the relative position between the underwater vehicle 4 and the connecting device 6 .

In the particular case described and illustrated here , the connecting device 6 comprises two sensors 25 of an optical type , preferably video cameras or photo cameras . Each sensor 25 of an optical type is configured to detect the position and/or the orientation of at least one particular identi fying element arranged on a portion of the underwater vehicle 4 facing the connecting device 6 during the connection of the connecting device 6 and the underwater vehicle 4 .

According to a variant of the present invention, not shown in the attached figures , each sensor 25 is of an acoustic type such as , for example , a sonar .

According to a further variant of the present invention, not shown in the attached figures , the connecting device 6 comprises at least one , preferably laser, positioning element configured to emit a light beam detectable by the sensors 25 so as to veri fy the correct alignment of the connecting device 6 with the underwater vehicle 4 .

Moreover, the connecting system 5 comprises a control unit 26 ( Figure 1 ) configured to control the actuation assembly 8 so as to arrange the connecting device 6 at the underwater vehicle 4 and to orient the connecting device 6 towards the underwater vehicle 4 during the connection of the connecting device 6 and the underwater vehicle 4 .

In particular, the control unit 26 is connected to the sensors 25 and is configured to control the actuation assembly 8 in a closed loop as a function of the relative position detected by the sensors 25 .

In use and with reference to Figure 1 , when the underwater vehicle 4 arrives in the vicinity of the floating vehicle 3 , the control unit 26 controls the actuation assembly 8 by actuating the actuators 18 , 19 and 20 so as to control the position and the orientation of the connecting device 6 with respect to the underwater vehicle 4 .

In particular, the control unit 26 controls the actuation assembly 8 in a closed loop as a function of the relative position detected by the sensors 25 so that the connecting device 6 follows the position and the orientation of the underwater vehicle 4 .

With reference to Figure 5 , each mechanical connector 23 engages the underwater vehicle 4 and the inductive connector 24 is connected electrically and for data exchange to the underwater vehicle 4 .

Once the underwater vehicle 4 is coupled to the connecting device 6 , the actuators 18 , 19 and 20 of the actuation assembly 8 are placed in a neutral configuration, so as to allow the free rotation of the elongated element 10 with respect to the support element 9 , the free rotation of the elongated element 11 with respect to the elongated element 10 , and the free rotation of the connecting device 6 about the connecting j oint 21 . When the floating vehicle

3 carries the underwater vehicle 4 connected to the connecting system 5 , it is thus possible to avoid that the articulated arm 7 is subj ected to hydrodynamic forces stemming from the mass and volume of the underwater vehicle

4 .

With reference to Figure 6 , in the presence of favourable environmental and meteorological conditions , the connection of the underwater vehicle 4 and the connecting device 6 is carried out close to the surface of the body of water 2 or partially above the surface of the body of water 2 .

In this scenario , the underwater vehicle 4 is arranged at the surface o f the body of water 2 and the control unit 26 controls the actuation assembly 8 by actuating the actuator 20 so as to rotate the body 17 with respect to the body 16 about the rotation axis R3 and arrange the connecting device 6 in the vicinity of the underwater vehicle 4 .

Finally, it is evident that variations can be made to the present invention with respect to the embodiments described with reference to the accompanying Figures without , however, departing from the scope of protection of the claims .