Autonomous station for storing a plurality of AUVs and its implementation method.

Abstract

Title: Autonomous Storage Station for a Plurality of AUVs and its Implementation Method. The invention relates to an assembly comprising AUVs (200) and an AUV storage station (100) anchored to the seabed, as well as a method for storing the AUVs (200), the method comprising a phase of anchoring the plurality of AUVs (200) to the submerged collection cable (130) of the storage station (100). Figure for the abstract: Fig. 1A

Description

Title of the invention: Autonomous station for storing a plurality of AUVs and its implementation method. Technical field

[0001] The present invention relates to the field of fleet management of autonomous underwater vehicles, usually referred to by the acronym AUVs from the English term Autonomous Underwater Vehicle.

[0002] More specifically, the invention relates to the field of AUV recovery at the end of a mission. STATE OF THE ART

[0003] For applications of collecting information related to environmental fauna and flora, or geophysical measurements, recent solutions are based on the deployment of AUVs.

[0004] An important step is to recover the AUVs at the end of the mission on board a ship.

[0005] This recovery step is often complex and time-consuming.

[0006] Systems for recovering an autonomous underwater vehicle (AUV) from a manned or remotely operated surface vessel are known. Such systems are described in patents FR2904288A1, US20230294798A1 and KR20140127376A.

[0007] Patent EP3213122 describes a device for deploying and recovering flotillas of autonomous underwater vehicles used in oil seismic surveys. In addition to the free-floating underwater vehicles, it requires three components: a dedicated vessel, a remotely operated vehicle (ROV), and an underwater elevator. Such a system is complex to operate. It requires highly qualified personnel and, moreover, has high manufacturing and maintenance costs.

[0008] This complexity of AUV recovery is all the more detrimental since the most recent information collection and monitoring solutions are based on fleets of AUVs, each fleet comprising several AUVs, or even several dozen AUVs.

[0009] One object of the present invention is to meet at least some of the limitations of prior solutions.

[0010] Another object of the present invention is to propose a solution to make the recovery of several AUVs easier and at satisfactory costs, in particular by eliminating the need for a ship to be present on site.

[0011] The other objects, features and advantages of the present invention will become apparent from an examination of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY

[0012] To achieve this objective, according to one embodiment, an assembly comprising • a plurality of autonomous underwater vehicles (AUVs), each comprising at least one propulsion device, a control device configured to control the propulsion device, and an acoustic communication device configured to receive acoustic signals, • a storage system, preferably autonomous, for a plurality of autonomous underwater vehicles (AUVs), the storage system comprising at least one storage station.

[0013] At least one storage station comprises: • a cable for collecting AUVs, • at least one mooring device configured to moor the collection cable to the seabed, and preferably including at least one ballast intended to rest on the seabed, and • at least one float exhibiting positive buoyancy in water and attached to the collection cable such that the collection cable extends between the float and the mooring device, • an acoustic signal transmitter, preferably cable-connected, and configured to send acoustic signals to the AUV's acoustic communication device,

[0014] Furthermore, each AUV includes at least one lashing device configured to lay the AUV to the cable. For each AUV, the control device is configured to command the propulsion device, at least according to the acoustic signals received by the AUV, in order to bring the AUV into a lashing configuration with the cable. The assembly is configured so that the AUVs of the plurality of AUVs are lashed, preferably simultaneously, to the collection cable; that is to say, at the same instant, several AUVs can be lashed, and therefore fixed, to the collection cable, the lashing step having been triggered at different or identical times.

[0015] According to another object, a method for storing a plurality of autonomous underwater vehicles (AUVs) on at least one storage station of an assembly as defined above is provided. The method includes a phase of docking the plurality of AUVs to the submerged collection cable of the storage station.

[0016] According to another object, a method for recovering a plurality of autonomous underwater vehicles (AUVs) is provided, the recovery method comprising the steps of the storage method defined above and further comprising a step of raising, at the water's surface, the collection cable to which the plurality of AUVs are attached. The recovery method may further include a step of raising the AUVs attached to the collection cable, for example, by a ship or an aircraft. The recovery method may further include a step of detaching the AUVs from the collection cable.

[0017] Thus, unlike existing solutions for recovering a fleet of AUVs, the proposed solution involves a collection phase for the AUVs that is entirely separate from the phase of bringing the AUVs aboard a ship. These two phases become independent, both in terms of timing and the means employed; in particular, the collection phase does not require the presence of a surface vessel. AUV collection and AUV retrieval can therefore be carried out entirely asynchronously. In this respect at least, the invention offers a radically different approach from prior art solutions.

[0018] Furthermore, the collection phase can be carried out in a completely autonomous manner, that is to say without human intervention, therefore without piloting from a ship or from a human-piloted vehicle of the ROV (remotely operated vehicle) type.

[0019] Thus, this solution allows for the simple and efficient collection of AUVs at the end of their missions by storing them on the cable. The device therefore forms an autonomous AUV storage station. This solution ensures the safe retrieval of AUVs by preventing their dispersal at the end of their missions, for example, due to ocean currents. Furthermore, this solution avoids the energy consumption of the AUVs while they await retrieval from the station by a surface vessel. A larger portion of the AUVs' energy autonomy can therefore be used for their missions.

[0020] To bring the AUVs aboard a ship or aircraft, it is simply a matter of raising the cable to the surface. This solution is much simpler and more reliable than maintaining a cable from a ship or aircraft. In particular, the heaving motions imposed on the ship by the swell, and therefore transmitted to the cable, make it difficult to guide the AUVs and secure them to the cable. Some existing solutions include mechanisms to compensate for these heaving motions, but these mechanisms are expensive and can only be installed on large lifting cranes aboard large ships.

[0021] Furthermore, during the development of the present invention, it proved complex to collect an entire fleet of AUVs in a basket or cage. Indeed, unless complex communication and sensor systems are deployed, AUVs frequently collide in close proximity to the collection basket. These collisions can damage the AUVs or at least cause them to lose their trajectory and overshoot their target. They must then perform complex maneuvers to return to the basket, which is now behind them. During the development of the present invention, synchronizing the AUVs so that their approach maneuvers to the basket are successive and do not generate collisions was considered. This solution proved unsatisfactory in terms of collection time, particularly for large fleets of AUVs or for applications requiring a rapid collection phase.

[0022] Furthermore, the storage stations according to the invention have a small footprint and a low weight. They are therefore easy to store, transport and operate.

[0023] Finally, the storage stations according to the invention induce a low cost of construction, operation and maintenance because they make it possible to do without many pieces of equipment compared to known solutions.

[0024] According to another object, a storage system for a plurality of autonomous underwater vehicles (AUVs) is provided, each comprising at least one propulsion device, a control device configured to control the propulsion device, an acoustic communication device configured to receive acoustic signals, the storage system comprising at least one storage station, the at least one storage station comprising: • a cable for collecting AUVs, • at least one mooring device configured to moor the collection cable to the seabed, and preferably including at least one ballast intended to rest on the seabed, and • at least one float exhibiting positive buoyancy in water and attached to the collection cable such that the collection cable extends between the float and the mooring device, • an acoustic signal transmitter, preferably attached to the cable, and configured to send acoustic signals to the AUVs, • a plurality of docking zones, each zone being configured to accommodate one AUV from the plurality of AUVs.

[0025] According to another object, a storage station for a plurality of autonomous underwater vehicles (AUVs) is provided. This storage station can be operated and claimed independently of the objects mentioned above, in particular independently of the AUVs. The storage station comprises at least one AUV collection cable and an acoustic signal transmitter, preferably attached to the cable, and configured to send acoustic signals to the AUVs. All features will be described subsequently in Description Detailed information regarding storage stations can be combined with this object. The storage system does not necessarily include AUVs.

[0026] According to one example, the storage system comprises the AUVs. In this case, preferably, each AUV includes at least one lashing device configured to lay the AUV to the cable. For each AUV, the control device is configured to command the propulsion device, at least based on acoustic signals received by the AUV, to bring the AUV into a lashing configuration with the cable, the system being configured so that the AUVs of the plurality of AUVs are lashed, preferably simultaneously, to the collection cable.

[0027] According to this object, the mooring device configured to moor the collection cable to the seabed is optional. The collection cable can be held in the water by at least one of the following: a buoy floating on the water's surface, a vessel, or an aircraft capable of hovering, such as a helicopter.

[0028] According to a first option, the cable has a plurality of stops. Preferably, the stops are evenly distributed along the cable. The spacing between two stops forms an anchoring zone for an AUV. Optionally, the distance DI50 separating two stops, when the cable is positioned in water, is greater than the length L200 of an AUV.

[0029] This first option can be used regardless of whether the cable has a ballast resting on the seabed. For example, the stoppers of the collection cable can be used with a cable one end of which is held by an aircraft such as a helicopter or a surface vessel during the AUV mooring and collection phases. Thus, all the features relating to the stoppers can be claimed independently of the features relating to the mooring of the storage station. All the features of the storage system described and illustrated above and below are compatible with this embodiment of the collection cable including stoppers.

[0030] According to a second option, alternative or combinable with the first option, the lashing device and the cable are configured so that when the collection cable is in contact with the lashing device, a movement of the AUV, preferably towards the rear, relative to the collection cable triggers the locking of the cable in the lashing device.

[0031] Advantageously, the locking device is entirely passive. For example, it does not include any actuator, such as a motorized one, for locking and unlocking the AUV on the cable. This significantly increases the reliability of the device and its service life. Furthermore, it greatly simplifies the design of the AUV and reduces its cost. For example, there is no actuator and battery powering the actuators. This solution is therefore particularly effective for deploying a fleet of numerous AUVs.

[0032] According to one example, the lashing device comprises: - a housing with an opening to allow the AUV to bring a section of the cable into the housing by a movement of the AUV oblique to a principal direction in which the cable extends, preferably in a direction perpendicular to a principal direction in which the cable extends, - a locking device comprising a locking member, such as a locking finger. The locking member is configured to close the opening and prevent the cable section from exiting the housing under the effect of a movement of the AUV oblique to a main direction in which the cable extends.

[0033] The locking member is elastically articulated on the housing, so as to present: - a blocking configuration, in which it rests against a seat in the housing and thus blocks the opening of the housing and, - an opening configuration, in which it is moved away from the seat, thus allowing access to the accommodation through the opening

[0034] The transition from the locked configuration to the open configuration is achieved under the effect of a force applied to the locking element. The AUV is configured so that the cable exerts this force when the AUV moves relative to the cable positioned in contact with it.

[0035] The locking member is rotationally articulated on the AUV so as to pivot to switch from the locked configuration to the open configuration and vice versa. Preferably, this pivoting occurs around an axis substantially perpendicular to a direction of advance of the AUV.

[0036] Preferably this pivoting takes place around an axis substantially parallel to a main direction along which the cable extends when the AUV is attached to the cable.

[0037] Preferably the locking device includes an elastic tab or a spring exerting on the locking member the force tending to keep it pressed against the seat (locking configuration).

[0038] For example, when the AUV is secured to the cable, that is, when the cable is inserted into the locking device and the latter is in the locked position, then the AUV cannot detach from the cable. In particular, the AUV cannot detach from the cable by a transverse or oblique movement to the cable direction. On the other hand, the AUV can slide along the cable, for example under the effect of gravity out of the water or even in the water.

[0039] According to one example, the locking member pivots to move away from the seat, thus allowing access to the housing through the opening.

[0040] Thus, when the locking member leaves the seat, it allows the cable to pass through the opening, in particular when the AUV moves in a direction oblique to a main direction in which the cable extends, preferably in a direction perpendicular to a main direction in which the cable extends.

[0041] According to one example, the AUV is configured so as to position the locking member against the cable and so that the propulsion device generates a force enabling the locking member to move from the rest position to the position of

[0042] According to one example, the housing is formed by a ring having an opening closed by the locking member.

[0043] In one example, the lashing device forms a hook. In another example, the lashing device forms a carabiner system with a locking gate.

[0044] According to one example, each AUV has a nose, a midplane, and two lateral sides extending on either side of the midplane. The midplane and each lateral side can be equipped with at least one tie-down device. The midplane is substantially vertical and contains the direction of travel of the AUV when it moves in a straight line.

[0045] It should be noted that all features relating to the AUV and all features relating to the mooring device can be exploited independently of the features relating to the collection cable of the storage station and, in particular, independently of the features relating to the fact that the cable has a ballast resting on the seabed. Thus, all features relating to the mooring devices can be claimed independently of the features relating to the mooring of the storage station.

[0046] Furthermore, the operation of the lashing device is independent of the presence of stops on the collection cable.

[0047] All the features of the recovery system described and illustrated above and below are combinable with this embodiment relating to the lashing device.

[0048] According to another object, which can be used and claimed independently of the objects mentioned above, in particular independently of a storage station, an AUV or a plurality of AUVs is provided. All the features that will be described subsequently in the detailed description concerning the AUVs are combinable with this object. In particular, all embodiments concerning the The lashing device, its connection to the AUV, and its operation can be operated and claimed independently of the storage station. Each AUV includes at least one lashing device configured to latch onto a cable. The lashing device is configured so that contact between the lashing device and the cable, or force exerted by the cable on the lashing device, causes the lashing device to latch onto the cable.

[0049] In one example, the lashing device is configured so that lashing the device to the cable is triggered by the AUV recoiling along the cable. In one example, the lashing device is located on a rear portion of the AUV or on at least one side of the AUV. In one example, the AUV comprises two thrusters, or propulsion devices located on a rear portion of the AUV, and the lashing device is located between the two thrusters. Preferably, the lashing device is located on a median plane of the AUV.

[0050] Alternatively, the lashing device is configured so that the lashing of the lashing device with the cable is triggered by a forward movement of the AUV. In this case, the lashing device is located on a forward portion or on the nose or on at least one side of the AUV. BRIEF DESCRIPTION OF THE FIGURES

[0051] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0052] [Fig. 1A] Figures IA and IB schematically represent an example of a storage system according to the invention. In [Fig. 1A], the AUVs converge towards the storage system. In [Fig. 1B], the AUVs are attached to the collection cable of the storage system.

[0053] [Fig.1B]

[0054] [Fig.2] Fig.2 schematically represents an example of an AUV configured for cooperate with the storage system.

[0055] [Fig.3A] [Fig.3A] schematically represents a portion of the AUV of [Fig.2], illustrating an example of a lashing device.

[0056] [Fig.3B] [Fig.3B] represents in an enlarged manner the lashing device of [Fig.3A].

[0057] [Fig.3C] The [Fig.3C] represents a variant of the lashing device illustrated in [Fig.3B].

[0058] [Fig.4] Fig.4 schematically represents a variant of the system of storage illustrated in [Fig.1A].

[0059] [Fig. 5] Fig. 5 schematically and functionally represents an example of communication relay.

[0060] [Fig.6] Fig.6 schematically represents a storage system including several storage stations.

[0061] [Fig. 7] Figures 7 and 8 schematically represent two further examples of storage system according to the invention.

[0062] [Fig.8]

[0063] [Fig.9] Figure [Fig.9] schematically represents a lifting stage of a pumping station storage on board a ship.

[0064] [Fig.1OA] Fig.1OA schematically represents, viewed from above, another example of an AUV configured to cooperate with the storage system.

[0065] [Fig.1OB] [Fig.1OB] is a rear view of this AUV illustrated in [Fig.1OA].

[0066] [Fig.1OC] Fig.1OC represents in an enlarged manner the docking device of the AUV of Fig.1OA,

[0067] [Fig. 11] Figures 11 and 12A and 12B schematically represent examples of lashing devices having at least one degree of freedom with respect to the body of the AUV.

[0068] Fig. 11 schematically represents an example of a rotating articulated lashing device on the body of the AUV.

[0069] [Fig.12A] [Fig.12B] Figures 12A and 12B schematically represent an example of a lashing device which can detach from the body of the AUV and remain attached to it by a flexible link.

[0070] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. DETAILED DESCRIPTION

[0071] Before proceeding to a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0072] According to one example, the lashing device and the cable are configured so that

[0073] that when the collection cable is in contact with the lashing device, a movement of the AUV relative to the collection cable triggers the locking of the cable in the lashing device. This locking is entirely passive and is automatically engaged by the movement of the AUV relative to the cable.

[0074] According to one example, the lashing device comprises a locking member elastically articulated on the AUV, and the lashing device and the cable are configured such that:

[0075] - when the collection cable is in contact with the locking device, a displacement of the AUV, forwards but also and preferably backwards, relative to the collection cable triggers a movement of the blocking device to reach an open configuration in which it allows the collection cable to access a housing.

[0076] - when the collection cable has entered the housing, the locking device returns elastically in a resting position, called the locking configuration, in which it prevents the collection cable from coming out of the housing.

[0077] Thus, this locking mechanism is entirely passive. It is therefore particularly reliable and robust.

[0078] According to one example, the locking element is rotationally articulated on the AUV so as to pivot to switch from the locked configuration to the open configuration and vice versa.

[0079] Preferably this pivoting takes place around an axis substantially perpendicular to a straight-line forward direction of the AUV.

[0080] Preferably the locking device includes an elastic tab or a spring exerting on the locking member a force tending to maintain it in the locking configuration.

[0081] According to one example, the lashing device is configured so that the AUV lashes onto the collection cable by a backward movement of the AUV relative to the cable. A lashing device configured to secure the AUV by a backward movement offers numerous advantages over a forward movement. Indeed, during the development of the present invention, it was found that a lashing device configured to secure the AUV by a backward movement significantly reduces the risk of the lashing device unintentionally lashing the AUV to elements other than the collection cable, such as fishing nets, drifting ropes, or vegetation like kelp, during navigation.

[0082] According to one example, the AUV has two propulsion devices positioned on a rear portion of the AUV, preferably symmetrically with respect to a median plane (ZX) of the AUV. The lashing device is positioned between the two propulsion devices. Thus, moving the AUV backward allows the cable to be easily brought into the lashing device between the two propulsion devices.

[0083] According to one example, the AUV has two guide surfaces, each extending from the lashing device and configured to guide the AUV relative to the collection cable towards the lashing device during a reverse movement of the AUV. These guide surfaces greatly improve the reliability of the docking stage of the incoming cable onto the collection cable.

[0084] According to one example, either in combination with or independently of the guide surfaces, the AUV comprises at least one movable element. This movable element is configured to assume a deployed position when the AUV is moving backward and a retracted position when the AUV is moving forward. In the deployed position, the movable element is configured to guide the AUV relative to the collection cable toward the lashing device during a backward movement of the AUV. This movable element makes it considerably easier to guide the cable toward, or even to, the lashing device.

[0085] According to one example, the AUV comprises two movable parts, located on either side of the lashing device and configured to form an angle θ between 45° and 160° in the deployed position and an angle θ' between -20° and +20° in the retracted position. This makes it considerably easier to guide the cable during the lashing phase when the movable parts are deployed, without significantly increasing the drag of the AUV during navigation when the movable parts are deployed.

[0086] According to one example, the transition from the deployed position to the retracted position is entirely ensured by a forward movement of the AUV X200 and the transition from the retracted position to the deployed position is entirely ensured by a backward movement of the AUV -X200. Thus, the alternating transition from the deployed position to the retracted position is done in a completely autonomous manner, i.e. without piloting, and passively, i.e. without energy.

[0087] According to one example, the AUV includes a sensor configured to identify whether the cable is blocked in the lashing device and the AUV is configured to transmit to a remote receiver, via its acoustic communication device, a signal indicating that the cable is blocked in the lashing device.

[0088] In one example, the lashing device is mounted movably on the body of the AUV, with at least one degree of freedom. This significantly reduces the risk of breakage of the lashing device. In one example, the lashing device is articulated to the AUV by a joint comprising at least one rotational degree of freedom, such as a pivot joint or a ball joint. Alternatively, or in combination, the lashing device is connected to the AUV by a deformable joint. This may be made of a deformable material such as an elastomer. Alternatively, the lashing device is configured to have a first configuration in which it is fixed, preferably with no degrees of freedom, to the body of the AUV, and a second configuration in which it is unfixed from the body of the AUV. remaining attached to the body only by one or more links, preferably soft or flexible.

[0089] According to one example, the AUV comprises a body having a nose, a rear and at least one side extending from the nose, at least one lashing device being located on at least one side or the seat, the body of the AUV being shaped so that when the AUV moves forward or preferably backward horizontally and in a straight line and the cable is in contact with the AUV, the cable slides to the lashing device.

[0090] According to one example, the AUV comprises two side flanges and at least two lashing devices, each side flange being equipped with at least one lashing device. Regardless of the direction in which the AUV approaches the cable, lashing is thus made simpler and more reliable.

[0091] According to one example, the lashing device and the cable are configured so that in lashing configuration the AUV retains a degree of sliding freedom relative to the cable along a main extension direction Z130 of the cable.

[0092] According to one example, the cable includes at least one stop preventing the AUVs from sliding downwards under the effect of their gravity. This allows the AUVs to be equipped with a simple and robust locking mechanism that does not require a perfectly reliable clamping force. Under the effect of the AUVs' gravity, whether in the water or out of the water when the cable is brought to the surface, the AUVs slide along the cable, stopped by at least one stop.

[0093] In one example, the collection cable comprises a plurality of stops distributed along the cable, the spacing between two stops forming an anchoring zone for an AUV. In one example, the distance DI50 separating two stops, when the cable is under tension, is greater than the length L200 of an AUV, the length of an AUV being measured along the direction of forward movement of the AUV, preferably D150 > 2* L200. In one example, the stops are formed by rings, regularly distributed along the length of the collection cable.

[0094] According to one example, the collection cable includes visual coding elements, these visual coding elements comprising or forming a sequence of several segments of a specific length. The sequence is configured so as to allow the AUV to optically assess its distance from the collection cable and / or to optically identify one or more docking zones assigned to the AUV. Preferably, the visual coding elements are taken from among light sources and / or retroluminescent elements and / or reflective elements.

[0095] According to one example, the AUV includes at least one optical sensor and the control device is configured to control the propulsion device, at least based on acoustic signals received from the transmitter and optical data provided by the optical sensor, to bring the AUV into the docking configuration with the cable.

[0096] According to one example, the method further includes a step of lifting on board a ship or aircraft the collection cable to which the plurality of AUVs are attached and a step of recovering the AUVs attached to the cable and detaching the AUVs from the cable.

[0097] According to one example, the process further includes, prior to the docking phase, a step of installing the storage system, the installation step including the immersion of the storage station.

[0098] According to one example, the device is configured so that the float is located below the surface of the water.

[0099] According to one example, the device is configured so that the cable extends in the water in a substantially vertical direction.

[0100] The storage station can also be described as a recovery station, in that it allows essential steps to be carried out for the recovery of AUVs.

[0101] According to one example, the cable has a first and a second end; the first end, referred to as the lower end, is attached to the mooring device, and the second end, referred to as the upper end, is attached to the float. Alternatively, the device is configured so that the cable extends in the water in a substantially horizontal direction. In this case, the storage station preferably comprises several floats.

[0102] According to one example, the lashing device comprises at least one weight preferably directly attached to the cable, for example at a so-called lower end of the cable. Alternatively, the lashing device comprises at least one connecting element linking the weight to the cable, the connecting element preferably being taken from a rope or a chain.

[0103] According to one example, the mooring device comprises several connecting members and several ballasts intended to rest on the seabed, each ballast being connected to the cable by at least one connecting member.

[0104] An example of a 1000 AUV storage system will now be described with reference to Figures IA and IB.

[0105] The system includes at least one AUV storage station 100, each storage station 100 includes a seabed mooring device 1, at least one float 120 having positive buoyancy in water and a cable, called a collection cable 130, connected to the mooring device and the float 120.

[0106] The storage station 100 is configured so that the mooring device 110 is fixed relative to the seabed 1. Thus, the storage station 100 has at least one end fixed relative to the seabed 1. The cable of The 130 collection cable, the mooring device, and the 120 float are configured so that the 130 cable is submerged when positioned at a distance from the ground. Specifically, the length of the 130 cable is adjusted so that the 120 float remains submerged regardless of wave height and tide.

[0107] Preferably, and as illustrated in the example of figures IA and IB, the cable 130 extends in a substantially vertical direction and at least oblique to the horizontal.

[0108] The storage station 100 further comprises at least one acoustic signal transmitter 140. This transmitter is attached to the collection cable 130. Preferably, it is fixed to the cable 130. Alternatively, it is fixed to the float or to another element connected to the cable 130.

[0109] This system is configured to store AUVs, referenced in Figures 200a, 200b, and 200c. In practice, the invention proves particularly effective when the AUVs form a fleet of several dozen, or even more than one hundred. The AUVs in the same fleet may move independently or in a coordinated manner, for example, as a swarm of coordinated AUVs.

[0110] In a perfectly conventional manner, each AUV 200 comprises at least:

[0111] - a propulsion device 202, comprising one or more thrusters and allowing movement and navigation underwater,

[0112] - an acoustic communication device 203 configured to receive acoustic signals from transmitter 140 of storage station 100. For example, this acoustic communication device 203 includes at least two hydrophones, preferably three or more hydrophones, allowing the localization of a source of acoustic signals such as transmitter 140 of collection cable 130 by triangulation.

[0113] - an AUV 200 control module that controls and commands the device propulsion 202 and processes information including signals received from the acoustic communication device 203.

[0114] The AUV 200 is configured to control its propulsion device 202, in particular according to the acoustic signals of the transmitter 140, so as to move towards the storage station 100 and its cable 130. The [Fig.lA] illustrates the AUVs 200 200a, 200b, 200c which move towards the cable.

[0115] The AUV 200 also includes at least one configured tie-down device of so as to attach the AUV 200 to the cable of storage station 100.

[0116] The cable 130 has several lashing zones, either separate or continuous, thus allowing several AUV 200s to be lashed to the same cable. In the illustrated example, the cable 130 has four lashing zones 1301-1304. In practice, this number will be much higher and may include more than ten or even more than fifty lashing zones.

[0117] The cable, as well as the storage station 100, are not fixed to a surface vessel.

[0118] Thus, the AUVs 200 can dock with the collection cable 130, for example when the control module determines a mission end. A mission end is determined, for example, when: an AUV 200 mission is completed, the AUV 200 receives a mission end signal, the AUV 200 has an energy level below a given threshold, a mission time has elapsed, a mission end time has elapsed, or the AUV 200 malfunctions.

[0119] Fig. 1B illustrates the AUVs 200a, 200b, 200c attached to the cable.

[0120] When several AUVs 200 are attached to cable 130, then it is possible to The 310 cable is brought to the surface, for example from a surface vessel or an aircraft such as a helicopter. A recovery step can then be carried out to retrieve the AUVs 200 attached to the cable and detach them from it. This step can be performed inside the vessel, aircraft, or on land.

[0121] The recovery of AUVs, in clusters and by this storage station 100, presents many advantages.

[0122] The storage and collection phase is conducted entirely autonomously by the AUVs 200, i.e., without intervention from a human operator. In particular, this storage and collection phase does not require the intervention of a surface vessel or an ROV.

[0123] Thus, the AUVs 200 can be collected at storage station 100 without any restrictions regarding the access zone for a surface vessel. For example, the AUVs 200 can reach storage station 100 even when weather conditions do not permit approach by a surface vessel.

[0124] Furthermore, the AUVs 200 can remain tethered to cable 130 for as long as necessary for storage before retrieval. During this entire tethering period, the AUVs 200 do not disperse, for example, due to ocean currents. Nor do they need to rest on the seabed, which could lead to its degradation, or even to the degradation of the AUVs themselves. A particularly advantageous feature is that the AUVs 200 consume no energy to maintain their position before retrieval during this entire period.

[0125] Moreover, this solution makes it possible to do without the use of an AUV recovery basket, the disadvantages of which have been mentioned previously.

[0126] Furthermore, since storage station 100 is placed on the seabed, the collection operations are not affected by wave height. The immersion measurement of the AUV is practically unaffected by wave height, provided that its immersion is greater than half the wave wavelength.

[0127] Furthermore, the 1000 storage system allows for the rapid collection of an entire cluster of AUVs, stored along the entire length of the cable at different levels. The speed of retrieval can thus be very advantageous. In particular, since the 200 AUVs can be distributed along the entire length of the cable, they can dock with the cable simultaneously, without the risk of collision that would cause them to lose their docking trajectory.

[0128] Furthermore, the cable offers rotational symmetry adapted to changes in current direction. It allows for the joining of the 200 AUVs over 360°.

[0129] In addition, the storage stations have a small footprint and low weight. They are therefore easy to store and transport.

[0130] Furthermore, raising the cable to the surface of a surface vessel can be done with conventional cable or net lifting equipment. The 1000 storage system is therefore particularly simple to operate.

[0131] Furthermore, several stations can be deployed and operated simultaneously. This solution is therefore particularly well suited for large fleets of 200 AUVs. Figure 6 illustrates an embodiment in which the 1000 storage system comprises a plurality of storage stations. In this schematic drawing, there are four 100a-100d stations.

[0132] It also presents particularly low production, operation and maintenance costs since it makes it possible to do without many complex pieces of equipment essential to known solutions, such as anti-ramming recovery mechanisms.

[0133] Preferably, the lashing device is configured to lay the AUV 200 to the cable while maintaining at least one degree of sliding freedom of the AUV 200 along a principal direction Z130 of cable extension. In the example illustrated in Figures IA and IB, this direction Z130 is substantially vertical, particularly in the absence of marine currents. This direction Z130 can be curved under the effect of marine currents, which apply a force to the cable and the subsurface float 120.

[0134] For example, the lashing device can form a ring inside which the cable can slide along the cable. Conversely, when the AUV 200 moves transversely in the Z130 direction, the lashing device prevents the AUV 200 from separating from the cable.

[0135] Stops 150 of the collection cable 130

[0136] Optionally, and as shown in Figures IA and IB, the cable is fitted with stops 150 configured to limit the movement of the lashing device and therefore of the AUV 200 along the cable 130. This prevents the AUV 200s from piling up on top of each other when the cable 130 is pulled, or under the effect of gravity, which could damage them.

[0137] The stops 150 take for example the form of rings fixed on the cable 130. If the lashing device forms a ring, then the stops 150 have a minimum section, taken along a plane perpendicular to the direction Z130, greater than a maximum section of the opening defined by the opening of the ring.

[0138] Thus, in this embodiment the stops 150 define lashing zones 1301-1304 distinct from each other on the cable 130. A lashing zone is defined by the cable section between two stops 150.

[0139] Preferably, the 1000 storage system is configured so that only one AUV 200 is moored in a given mooring area. This limits the risk of two adjacent AUV 200s colliding in the event of swell and especially during cable retrieval.

[0140] Preferably the stops 150 are arranged on the cable at regular intervals. For example, this interval is 2 meters.

[0141] Fig. IB illustrates the distance D150 between two stops 150 and the length L200 of an AUV.

[0142] In this example of [Fig.1B], D150 < L200. Thus, two juxtaposed AUV 200s can touch.

[0143] In the example illustrated in [Fig. 4], D150 > L200. Thus, two juxtaposed AUV 200s cannot touch. This prevents them from colliding under the effect of currents, swell during lifting, and during cable handling during the lifting phase. Preferably D150 > 1.2 * L200. Preferably D150 > 1.3 * L200.

[0144] It should be noted that all the features relating to the presence of stops 150 on the collection cable 130 can be exploited independently of whether the cable has a ballast resting on the seabed 1. For example, the stops 150 of the collection cable 130 can be used with a cable one end of which is held by an aircraft such as a helicopter or a surface vessel 700 during the AUV mooring and collection phases, as illustrated in [Fig. 9]. Thus, all the features relating to the stops 150 can be claimed independently of the features relating to the mooring of the storage station 100. All the features of the storage system 1000 described and illustrated above and below are compatible with the embodiment comprising a collection cable 130 equipped with stops 150.

[0145] Lashing device

[0146] An example of a lashing device will now be described with reference to Figures 2 and 3A to 3C.

[0147] It can be anticipated that the docking will be carried out by moving the AUV in a -X200 direction of reversing or in an X200 direction of forward movement of the AUV. These two The embodiments are illustrated in figures 3A to 3C. The embodiment with lashing according to a recoil displacement will now be described in detail.

[0148] According to one example, the lashing device 210 includes a housing 240 having an opening 241 to allow the AUV 200 to bring a section of the cable 130 into the housing 240 by a movement of the AUV 200 in a direction perpendicular to the main direction Z130 of the cable.

[0149] This housing 240 can form a groove. It can form a closed or open ring.

[0150] The lashing device 210 also includes a locking device comprising a locking member 230, such as a locking finger, configured to close the opening 241 and prevent the cable section 130 from coming out of the housing 240, for example under the effect of a movement of the AUV 200 oblique to the main direction Z130 in which the cable extends.

[0151] Preferably, the locking member 230 is elastically articulated on the housing, so as to present:

[0152] - a blocking configuration, in which it rests against a seat 222 of the housing 240 and thus closes the opening 241 of housing 240 and,

[0153] - an opening configuration, in which it is moved away from seat 222 allowing thus access to housing 240 through opening 241.

[0154] The AUV 200 is configured so that the transition from the blocking configuration to the opening configuration is obtained under the effect of a stress applied to the blocking member 230. The blocking member 230 is preferably articulated in rotation so as to pivot to transition from the blocking configuration to the opening configuration and vice versa.

[0155] The locking member 230 pivots away from the seat 222, thus allowing access to the housing 240 through the opening 241. Therefore, when the locking member 230 leaves the seat 222, it allows the cable to pass through the opening 241, particularly when the AUV 200 moves towards the cable in a direction perpendicular to the Z130 direction. The lashing device 210 thus forms a carabiner system with a locking gate.

[0156] When the cable is raised out of the water to retrieve the AUVs 200, the AUVs 200 are detached from the cable by applying force to the locking element 230, typically manual force exerted by one or more fingers of an operator, so as to move the locking element 230 from the locked position to the open position. In the open position, the cable is removed from the housing of the lashing device 210, and the AUV 200 is then detached from the cable 130. The cable is exited by passing it through the opening 241. Therefore, it is not necessary to slide the AUV 200 to one end of the cable to remove it.

[0157] Preferably, the pivoting of the locking member 230 takes place around an axis 231 substantially perpendicular to a forward direction X200 of the AUV. This forward direction X200 corresponds to a straight-line forward movement of the AUV.

[0158] Preferably this pivoting takes place around an axis 231 substantially parallel to the main direction Z130 along which the cable extends at the anchorage of the AUV 200 on the cable.

[0159] As illustrated in the example of [Fig. 3B], the locking member 230 has a first end 231 by which it is articulated on a portion 221 integral with the AUV 200 and a second end 232 configured to cooperate with seat 222 in order to at least partially close the opening 241. Preferably the lashing device 210 is configured so that the locking member 230 comes into contact with the seat 222. This allows the opening 241 to be completely closed.

[0160] Alternatively, the locking member 230, in its locking configuration, is not in contact with the seat 222. It is located at a distance from the latter. In this case, the locking member 230 is positioned sufficiently close to the seat 222 so that the distance between the locking member 230 and the seat 222 does not allow the cable to pass through.

[0161] Preferably, the locking device comprises an elastic tab or a spring exerting on the locking member 230 a force tending to keep it pressed against the seat. This elastic member is not shown. Alternatively, this elastic member may be formed by the locking member 230 itself.

[0162] The AUV 200 is configured so as to position the locking member 230 against the cable 130 and so that the propulsion device 202 generates a force enabling the locking member 230 to move from the rest position to the position of

[0163] The 210 lashing device is entirely passive. For example, it does not include any actuators, such as motorized ones, for locking and unlocking the AUV 200 on the cable. This significantly increases the device's reliability and lifespan. Furthermore, it greatly simplifies the design of the AUV 200 and reduces its cost. For example, there are no actuators or batteries to power them. This solution is therefore particularly effective for deploying a fleet of numerous AUV 200s.

[0164] When the AUV 200 is attached to the cable, i.e. when the cable is inserted into the locking device and the latter is in the locking configuration, then the AUV 200 cannot detach from the cable.

[0165] In particular, the AUV 200 cannot detach from the cable by a transverse or oblique displacement to the main direction Z130 of the cable. On the other hand, the AUV 200 can slide along the cable.

[0166] Preferably, and as illustrated in Figures 3A and 3B, the lashing device 210 is located on one side of the AUV. Thus, when the AUV 200 comes into contact with the cable and moves backward in the direction -X200, the cable moves closer to the lashing device 210. Preferably, the shell of the AUV 200 forms a guiding surface for the AUV 200 as it slides along the cable. This guiding surface may extend over a portion of its side 20111, 2012 and up to the lashing device 210. In [Fig. 3A], the reference numerals 130', 130”, 130”’ illustrate the successive positions of the cable relative to the body 1 of the AUV as the latter moves backward. This sliding occurs in a direction substantially parallel to the recoil direction -X200 of the AUV 200 and substantially perpendicular to the main direction Z130 along which the cable extends at the point of contact with the AUV.

[0167] The progressive recoil of the AUV thus leads to bringing the lashing device 210 closer to the cable, until the latter is locked in the lashing device 210. More precisely, the recoil of the AUV causes the cable to come into contact with the locking member 230 and to rotate the latter so as to enter the opening 241.

[0168] Preferably, the AUV 200 has a curved surface that flares out in the direction of the lashing device 210, so as to easily guide the cable towards the lashing device 210.

[0169] Thus, from the moment the AUV 200 moves back significantly towards the cable, the latter serves as a guide for the drone until the cable is inserted into the lashing device 210.

[0170] Preferably, the first end 221 of the locking member 230 is located closer to the rear portion 260 of the AUV 200 than to the seat 222, relative to the AUV's reverse direction -X200. Thus, when the AUV 200 moves backward, the cable's contact with the locking finger 230 causes the latter to pivot and the second end 232 of the member to move away from its seat 222. The locking member 230 then pivots to release the opening 241 of the housing 240.

[0171] As illustrated in [Fig. 3B], the lashing device 210 and the body 1 of the AUV are configured to form a cable guide 242 before its insertion into the housing 240. This guide 242 is located downstream of the opening 241 relative to the direction of travel of the AUV along its principal forward direction X200. This guide 242 is therefore located upstream of the opening 241 relative to the direction of travel of the AUV along its reverse direction -X200. This guide 242 has a guide portion 244, an upstream part of which defines an inlet 243 through which the cable enters. The guide portion 244 has a decreasing cross-section between the inlet 243 and the opening 241 of the housing 240. This cross-section 245 is illustrated in [Fig. 3B]. So, As the AUV moves backward in the direction -X200 opposite to its direction of advance X200, once the cable reaches the mouth 243, it is guided by the guide portion 244 to the entrance 241 of the housing 240.

[0172] The guiding device 242 can be defined by a wall formed by an extension 220 of the lashing device 210 defining the housing 240.

[0173] In the example illustrated in [Fig.3B], the locking member 230 is rotationally articulated on this extension 220. The seat 222 is carried by a side 2011, 2012 of the AUV.

[0174] A variant is illustrated in [Fig. 3C]. In this variant, the locking member 230 is articulated on a side 2011, 2012 of the AUV. The seat 222 is supported by an extension 220 of the lashing device 210 defining the housing 240.

[0175] In this [Fig.3B], two examples of lashing are illustrated. References 130a' to 130a””’ on the one hand and 130b' to 130b” on the other hand illustrate the successive positions in time of the AUV relative to the cable as the AUV moves backward.

[0176] References 130a' to 130a”'” correspond to cases in which the AUV 200 makes contact with the cable from its rear portion 260, the AUV 200 then sliding relative to the cable along its side 2011.

[0177] In position 130a' ” ” the cable is in contact with the locking member 230 and exerts on the latter a force which moves the second end 232 away from the locking member 230 relative to the seat 222.

[0178] In the example illustrated above, the lashing device is configured to secure the AUV by means of a backward movement of the AUV. This backward movement is along the -X200 direction. This embodiment has the advantage of considerably reducing the risk that the lashing device may unintentionally, during a navigation phase, lash the AUV to elements other than the collection cable, such as fishing nets, drifting ropes, or vegetation such as kelp. Alternatively, the lashing device can be configured to secure the AUV by means of a forward movement of the AUV along the X200 direction. This embodiment is also illustrated in Figures 3A to 3C. The front of the AUV then corresponds to reference numeral 206 and not to reference numeral 260, which illustrated the sill or the rear portion 260 of the AUV.All the features of these two embodiments are combinable and interchangeable.

[0179] Alternatively, the blocking device is positioned at another location on the AUV, for example at a median position on the AUV, for example on the nose of the AUV.

[0180] With reference to Figures 10A to 10C, another embodiment of an AUV will now be described. All the previously described characteristics of the AUV and the storage system remain perfectly valid for this embodiment and are therefore compatible with those of this new embodiment.

[0181] In this embodiment, the lashing device 210 is located on a rear portion 260 of the AUV. Thus, when the latter performs a reversing movement, its rear portion 260 comes into contact with the cable 130 to lashing the latter.

[0182] In the optional example described, the AUV 200 has two propulsion devices 202a and 202b located on a rear portion 260. These two propulsion devices 202a and 202b are situated on either side of a median plane ZX of the AUV, which is vertical when the AUV is moving horizontally. Advantageously, the docking device 210 is located between the two propulsion devices 202a and 202b.

[0183] The AUV 200 includes at least one guide surface 270 configured to guide the cable 130 to the lashing device 210 and the locking member 230 as the AUV reverses. During the development of the present invention, it became apparent that the maneuverability of an AUV 200 during a reversing phase can be limited. The presence of the guide surfaces 270 considerably facilitates the entry of the cable 130 into the lashing device 210.

[0184] Preferably, each guide surface 270 extends from the opening 241 of the lashing device 210.

[0185] Preferably, the AUV 200 comprises two guide surfaces 270 symmetrically arranged with respect to the median plane passing through the lashing device 210. Preferably, the lashing device is located on the median plane ZX of the AUV 200. As illustrated in Figures 10A and 10C, these two guide surfaces 270 then form a "V" or a portion of a "V" in a horizontal plane XY, when the AUV moves horizontally, typically along the X direction.

[0186] Optionally and advantageously, the lashing device 210 includes a movable member 250 configured to guide the cable 130 to the guide surface 270 or to the locking member 230 as the AUV recoils. The movable member 250 is configured to adopt:

[0187] - a first position 250a', called retracted, when the AUV advances X200. In In this position, the moving part 250 can extend primarily in a direction parallel to the forward direction X200 of the AUV or parallel to the median axis ZX of the AUV. In this position, the moving part 250 is thus positioned in the wake of the AUV, which reduces its friction during the forward movement of the AUV 200.

[0188] - a second position 250a, called deployed, when the AUV recoils -X200. In In this position, the movable member 250 extends in an oblique direction relative to the forward direction X200 of the AUV. It has a first end 251 fixed to the AUV and a free end 252. In this position 250a, the second end 252 is further from the median axis ZX of the AUV than the first end 251. It thus allows to form a guiding angle to guide the cable 130.

[0189] Advantageously, the transition from the deployed position 250a to the retracted position 250b occurs automatically under the influence of water force. The water tends to return the moving part 250 to the retracted position 250b when the AUV 200 moves forward X200 and tends to bring the moving part 250 into the deployed position 250a when the AUV moves backward. The deployment and retraction of the moving part 250 are carried out in a completely passive and automatic manner, without energy or control, which increases the reliability and robustness of the AUV 200.

[0190] In the illustrated example, the AUV 200 comprises two movable members 250, each of which has a deployed position 250a, 250a' and a retracted position 250b, 250b'. These two movable members form a portion of a "V". If the AUV has guide surfaces 270, then advantageously, in their deployed position 250b, 250b, the movable members extend the guide surfaces. The collection cable 130 can thus be guided over a greater distance. This makes it possible to compensate very effectively for any angular offset that the AUV may have in its recoil movement to secure the cable 130.

[0191] Figures 10A and 10C illustrate the different positions of cable 130 during the recoil of the AUV along the -X200 direction. References 130a' illustrate successive positions of the AUV 200 in which cable 130 is not in contact with the AUV. Reference figure 130a” illustrates a position of the AUV 200 in which the cable 130 is in contact with the movable member 250 in its deployed position 250a. Reference figures 130a”’ and 130”” illustrate successive positions of the AUV 200 in which the cable 130 is guided by the guide surface 270. Reference figure 130a’”” illustrates a position of the AUV 200 in which the cable 130 has entered the housing 240 of the lashing device 210 and is locked in the latter by the locking member 230.

[0192] According to one embodiment, when the two movable members 250 are in the deployed position 250a, 250b, they together form an angular sector a greater than 45° and preferably between 60° and 160° and preferably between 70° and 160°, which allows very efficient guidance of the cable even when at the beginning of the maneuver the median plane ZX of the AUV 200 is not perfectly aligned with the axis Z130 of the collection cable 130. In the example illustrated in figures 10A and 10C, this angle a is 90°.

[0193] When the two movable members 250 are in the retracted position 250a', 250b', together they form an angular sector a' less than 45° and preferably less than 20° and preferably between -20° and +20°, and preferably between -10° and +10°, which reduces their friction during the advance of the AUV 200. In the example illustrated in figures 10A and 10C, in the retracted position, this angle a' is 0°.

[0194] According to one example, the movable member 250 is elastically deformable. It is configured so that its elasticity allows it to adopt the deployed position 250a when the AUV moves backward, for example, under the effect of water resistance when the inlet moves backward. Its elasticity allows it to return to the retracted position 250b when the AUV moves forward X200.

[0195] In this example, the movable part 250 can be fixed rigidly to the AUV, without articulation.

[0196] Alternatively, the movable member 250 can be articulated on the AUV, for example with a rotational joint to move from the deployed position 250a to the retracted position 250b and vice versa. This rotational joint can be performed around a vertical axis Z when the AUV moves in a horizontal plane XY.

[0197] Finally, according to another embodiment, the movable part 250 can be articulated on the AUV 200 while exhibiting a flexibility allowing its elastic deformation.

[0198] The presence of a movable element 250 is not limited to a lashing device 210 positioned on the rear portion 260 of the AUV. Lashing devices 210 positioned on other portions of the AUV can also be equipped with a movable element 250. Thus, in [Fig. 1OA], a lashing device 210 is shown on a side 2012 of the AUV 210 and includes a movable element 250 for guiding the cable 130. This lashing device 210 can, for example, be identical to those illustrated and described with reference to Figures 3A and 3B. A recoil movement of the AUV brings the movable element 250 into the deployed position 250a, and a forward movement of the AUV automatically returns the movable element 250 to the retracted position 250a'.

[0199] It will be noted that, according to an embodiment not illustrated, the lashing device 210 includes a movable member 250 for guiding the cable 130 to the lashing device 210, but does not include a fixed guiding surface 270.

[0200] In the example illustrated in [Fig.1OA] at 10C, the AUV 200 includes two additional propulsion devices 2021, 2021, configured to move the AUV vertically when the AUV 200 is moving in a horizontal plane ZX.

[0201] Similarly, the AUV 200 may include a lashing sensor configured to detect when the AUV 200 is lashed to the cable. For example, this may be a sensor configured to detect movement of the locking member 230. This movement may correspond to a movement away from its seat 222 followed by a movement back towards its seat 222. It may, for example, be a magnetic sensor or an optical sensor. Alternatively, the sensor equipping the AUV 200 may be provided to detect the presence of the cable, for example by means of an optical sensor. This optical sensor may detect the presence of the cable inside the housing 240. Alternatively, the cable 130 may be provided to have an element to which a sensor of the AUV 200 is magnetically sensitive when the cable is positioned in housing 240. This element can be supported by a sheath or a core of cable 130.

[0202] Optionally, the AUV 200 may also be provided to include an acoustic signal transmitter for transmitting the cable locking status. Preferably, the lashing sensor transmits the data it captures to the AUV control module, which can then transfer data relating to the lashing of the AUV 200 to the collection station or any other remote sub-assembly 400; an example of a remote sub-assembly 400 will be detailed later, etc.

[0203] According to one embodiment, it can be provided that the lashing device 210 is not fixed to the body 201 of the AUV, i.e., fixed without any degree of freedom of the body 201. Thus, it can be provided that the lashing device 210 has at least one degree of freedom with respect to the body 201 of the AUV 200.

[0204] This has the advantage of reducing the risk of damage to the AUV during the retrieval step of the collection cable 130 to which the AUVs are attached. When the AUVs are retrieved by pulling the collection cable 130, the latter is under considerable tension due to the weight of the multiple attached AUVs. During the development of the present invention, it was found that forces, primarily generated by the weight of the AUV 200 and by wave motion when the AUV is near the surface, are concentrated on the lashing device 210. These forces can result, for example, in a torque exerted on the lashing device 210. These forces can lead to its failure or to damage to the body of the AUV.By providing at least one degree of freedom between the lashing device 210 and the body 201 of the AUV, the latter can be placed in a position which limits or even eliminates the forces exerted between the lashing device 210 and the body of the AUV 201.

[0205] For example, it can be foreseen that the lashing device 210 is mounted movably on the AUV 200, with at least one degree of mobility.

[0206] According to one example, the lashing device 210 is articulated on the AUV 200 by a joint comprising at least one rotational degree of freedom, such as a pivot joint or a ball joint. Figure 11 illustrates an example in which the lashing device 210 has a base 280 comprising a pivot joint 281, 282 allowing rotation about an axis AL. This axis AL is, for example, parallel to a transverse direction Y of the AUV 200. Portion 281 is fixed to the body of the AUV 201, and portion 282 is fixed, by this rotation, to the locking member 230.

[0207] Alternatively or in combination with the pivot joint 281, 282, it may be provided that the lashing device 210 has a pivot joint 283 configured to allow rotation around an axis A2 different from AL A2 is for example parallel to the direction Z which corresponds to the vertical when the AUV 200 moves horizontally.

[0208] This embodiment can also be used to equip a drone which provides for docking by a recoil movement or a forward movement.

[0209] When the lashing device 210 is located on the rear portion 260 of the AUV 200, for example as in the example of Figures 10A-10C, it can be provided that the housing 240 and the locking device 230 are articulated on a pivot joint allowing rotation around an axis parallel to the Y direction with respect to the body 201.

[0210] According to another embodiment, the base 280 is provided to form a deformable joint. This base 280 thus allows displacement of the housing 240 and the locking member 230 relative to the body 201. Preferably, the base 280 allows deformation in at least two directions. For example, the base 280 comprises or is made of an elastomer.

[0211] According to another embodiment, illustrated in Figures 12A and 12B, the lashing device 210 can be completely detached from the body 201 of the AUV 200. When the AUV 200 is not lashed to the cable 130, the lashing device 210 is attached to the body 201 of the AUV 200. This situation is illustrated in [Fig. 12A].

[0212] When the AUV 200 is secured to the cable 130, the lashing device 210 detaches from the body 201 of the AUV 200. This situation is illustrated in [Fig. 12B]. In this configuration, the lashing device 210 remains connected to the AUV by a link 287, preferably flexible, for example, a cable or rope. The length of this link 287 allows the body 201 of the AUV 200 to adopt the position imposed upon it, for example, by gravity, a current, or swell, while the lashing device 110 remains firmly attached to the cable 130 and possibly to the stop 150 of the cable 130.

[0213] Preferably, this disengagement takes place automatically, for example when the lashing sensor detects the presence of cable 130 in housing 240.

[0214] According to the non-limiting example shown, the lashing device 210 comprises a base 281 that is fixed, preferably fully fixed (i.e., without any degrees of freedom), to the body 201 when the lashing device 210 is attached to the body 201. For example, and only optionally, the body 201 has a cavity 290 shaped to house the base 280. The AUV 200 includes a locking device configured to lock the base 280 inside the cavity 290. This locking can be magnetic. Alternatively, a mechanical locking mechanism may be provided. For example, one of the body 201 and the base 280 includes an actuator 284 configured to move a bolt 285 which cooperates with a strike plate 286 carried by the other of the body 201 and the base 280. In the illustrated example, the actuator and the bolt are carried by the base 280 and the strike plate is formed by the body 201.

[0215] The link 287 is folded inside the base 280 or inside the body 201. This link has one end 288 connected to the base 280 and the end 289 connected to the body 201.

[0216] When the cable 130 is secured to the lashing device 210, the locking device is configured to unlock the base 280 from the cavity 290. The lashing device 210 therefore remains secured to the cable 130. The body 201 of the AUV can detach from the base 280 while remaining connected to it and thus to the cable 130 via the link 287. The AUV 200 thus remains secured to the collection cable 130 via the link 287 and the lashing device 210.

[0217] It should be noted that cavity 290 is only optional and that the whole of the preceding description is perfectly valid in the absence of cavity 290 housing base 280.

[0218] It should be noted that all the features relating to the lashing device 210 can be exploited independently of whether the cable has a ballast resting on the seabed 1. For example, the lashing device 210 can be used with a cable one end of which is held by an aircraft such as a helicopter or a surface vessel 700 during the lashing and collection phases of AUVs. Thus, all the features relating to the lashing devices can be claimed independently of the features relating to the lashing of the storage station 100. Furthermore, the operation of the lashing device 210 is independent of the presence of stops 150 on the collection cable 130.

[0219] All the features of the storage system 1000 described and illustrated above and below can be combined with this embodiment relating to the lashing device 210.

[0220] Other subsets

[0221] In addition to the storage station(s), the 1000 storage system may include one or more of the following optional subsets:

[0222] - A device for determining marine currents such as tables, a buoy drifting, or a Loch Doppler.

[0223] - A communication relay having a first communication channel by underwater acoustic signals and a second communication channel using radio signals.

[0224] - An unmanned autonomous or remotely operated boat, usually referred to as an SUV (Surface Unmanned Vehicle). The SUV is equipped with an acoustic signal communication channel compatible with said relay.

[0225] - Additional components configured for system deployment 1000 storage units at any given time, before or after the mission. These components External examples include: a non-dedicated boat, a satellite positioning system (GPS, Galileo, Glonass, Compass, etc.),

[0226] The following paragraphs specify optional characteristics that the various components of the 1000 storage system may have.

[0227] Collection station

[0228] In addition to the mooring device 110, the float 120, the collection cable 130, and the acoustic signal transmitter 140, the autonomous collection station 100 may include the following optional elements. These elements are preferably positioned from the bottom 1 towards the surface when the storage station 100 is deployed:

[0229] - A buoy 170 for example connected to the subsurface float 120 by a simple rope

[0230] This buoy 170 can serve as a signaling device for surface vessels or aircraft. It can then display a flag or pennant 172, or a light. This makes it easier to identify the position of the storage station 100. Alternatively or in combination, this buoy 170 can include a radio frequency communication device with remote communication devices 400. Also alternatively or in combination, this buoy 170 can include a communication device 175 using acoustic signals. This allows communication with AUVs 200 or collection stations 100. Advantageously, the buoy 170 includes a radio frequency communication device, such as a repeater 500.The radio frequency communication device and a communication device 175 using acoustic signals thus make it possible to transfer to the AUVs 200 information or instructions received from remote communication devices 400 located out of the water or on the surface, or to transmit to the latter information received from the AUVs 200. For example, the buoy 170 is connected to the storage station 100 by a link 176 such as a rope or a cable.

[0231] - a float 180 attached to the buoy by a positive buoyancy rope. This allows for example to be recovered more easily the collection cable 130. For example the float 180 is connected to the buoy 170 or to the storage station 100 by a link 181 such as a cable or a rope.

[0232] - an anchor 111 and its chain. The anchor 111 is, for example, attached to the ballast 110 or to the cable 130. Anchor 111 helps stabilize the mooring of storage station 100 to the seabed 1.

[0233] - at least one light source 160. This light source is configured to Illuminate at least certain areas of the cable. This facilitates the optical guidance of the AUV 200s towards the cable and their attachment to it when light conditions are low, typically at great depths. It is preferable fixed to the cable 130. For this purpose, it can be provided that at least one of the following light sources equips the storage station 100: battery-powered light sources such as LEDs (light-emitting lamps) or light sticks, typically chemically activated. Preferably, the guide light sources are attached between two cable stops 150 or to the stops 150. Alternatively, the light sources 160 are each formed by a stop. This allows the AUVs to identify each of the docking zones even more precisely.

[0234] According to one example, the 130 collection cable includes visual coding elements. These elements comprise or form a sequence of several segments of a specific length. This sequence is configured to allow the UAV to perform at least one of the following two functions:

[0235] - to allow the AUV to assess its distance to the collection cable 130. This allows it to identify more precisely its docking zone.

[0236] - to allow the AUV to optically identify one or more docking zones which It has / have been assigned to it. It is indeed possible to anticipate that certain AUVs will be designed to dock only in specific docking zones, corresponding, for example, to an upper section of the cable. This will allow for the easy retrieval onto a ship of a group of AUVs that need to be recovered more frequently than another group, or for concentrating the AUVs to be retrieved on docking zones near the surface.

[0237] According to one example, the visual coding elements are the light sources 160. These can then be luminous rings or strips placed along the cable 130, for example, placed along the same lashing area. Alternatively, the visual coding elements are retroluminescent or light-reflecting elements. The light can be supplied by sources placed along the cable 130.

[0238] Alternatively, the light source is carried by the AUV 200 and the cable 130 is equipped with retroluminescent segments. In both cases, the sequence can be an alternation of dark and light segments, retroluminescent or not, or even of different colors arranged in a specific way. Combined, the collection cable 130 can be provided with one or more light sources for one or more anchoring zones and the AUV can also carry a light source to illuminate the cable 130.

[0239] AUV

[0240] Examples of AUV 200 are illustrated in [Fig. 2] and 10A-10C. In addition to the propulsion unit 202, the acoustic communication unit 203, the control module, and the optional docking device 210, the AUV 200 may include one or more of the following optional components. These components may be integrated into a shell of the AUV body 201:

[0241] - a source of electrical energy,

[0242] - a control and command device,

[0243] - a reference of attitude and direction

[0244] - at least one pressure sensor,

[0245] - at least one optical sensor, for example a camera 204,205, and its unit Associated image processing. Preferably, the optical sensor is configured to detect the presence of the cable and provide data to the control device so that the latter guides the AUV 200 towards the cable and, more specifically, towards the docking zones. Preferably, the control device takes into account both acoustic and optical signals to guide the AUV 200 and bring it into contact with the cable for docking. Preferably, the control device takes into account acoustic signals in a first approach phase to the collection station 100, and then, in a second phase, takes into account optical data to dock with the cable 130. The first phase allows guidance when the AUV is several meters, or even tens, hundreds, or kilometers away from the cable. The second phase allows guidance when the AUV is less than 2 meters from the cable.During this second phase, the control device preferably also takes into account the acoustic signals emitted by the transmitter 140 of the storage station 100.

[0246] In the example illustrated in [Fig.2] the optical sensor includes at least one camera and preferably a so-called front camera 205 configured to capture images located in front of the AUV 200 and a so-called vertical camera 204 configured to capture images located below the AUV 200.

[0247] Whether or not the collection cable 130 has one or more light sources 160, the AUV may be provided with an onboard light source. This can project light onto the cable to facilitate the optical guidance of the AUV 200 on the cable 130 during the docking phase. This source is preferably positioned to illuminate towards the rear of the AUV 200 if the latter is configured to dock with the cable 130 by a recoil movement -X200, as illustrated in [Fig. 1OB]. This source is preferably positioned to illuminate towards the front of the AUV 200, as illustrated in [Fig. 2], if the latter is configured to dock with the cable 130 by a forward movement X200.

[0248] Communication relay

[0249] Optionally, the storage system 1000 includes a communication relay 500. This relay is schematically illustrated in Figures IA, IB and [Fig. 2]. Preferably, this relay is integrated into the buoy 170. It comprises a body 501 on or within which at least some of the following elements are positioned:

[0250] - an underwater communication channel using acoustic signals 502,

[0251] - a 503 surface communication module using radio signals,

[0252] - a 504 radiolocation module, for example via satellite (GPS etc.),

[0253] - a 505 processing unit,

[0254] - a source of electrical energy 506.

[0255] Also optionally, the 1000 storage system includes an SUV 300 which integrates the aforementioned 500 communication relay and its own means of propulsion and guidance.

[0256] Example of a recovery process

[0257] An example of a recovery process will now be described.

[0258] Preparation and launching of the AUVs 200

[0259] Prior to the immersion of the AUVs 200, the operator records in memory processing units of each AUV 200 at least some of the following information:

[0260] - The X and Y coordinates, in an absolute reference frame, of the point where the AUV 200 is to to hold pending the arrival of the storage station 100 assigned to it,

[0261] - The stationary immersion instruction pending the acoustic signal enabling the storage station rally

[0262] - The estimated time of assembly,

[0263] - The immersion instruction for approaching the storage station, different for each AUV, for the purpose of attaching it to the cable,

[0264] - The immersion depth of the acoustic emitter of the storage station 100 and the characteristics of its acoustic signals: for example recurrence, frequency and waveform.

[0265] Then a flotilla of AUVs 200 is put into the water in order to conduct a mission, for example of reconnaissance of the seabed in a defined area preferably in an absolute reference frame, that is to say with known geographical coordinates.

[0266] Preparation and setup of one or more stations

[0267] One or more autonomous storage stations for 200 AUVs are carried on board an opportunity vessel. Before the start of the rendezvous operations, the vessel rendezvouses with each mooring point of said stations whose coordinates are known in an absolute reference frame.

[0268] Preferably, the mooring coordinates are calculated so that the AUVs 200s reach their assigned station at the scheduled time facing the current.

[0269] The storage station(s) are put into the water, the cable lengths are adjusted so that the sub-surface float 120 is permanently submerged regardless of the swell height and tide.

[0270] Rallying of the 200 storage stations by the AUVs

[0271] 1. When the AUV needs to return to storage station 100, it determines the direction of the acoustic transmitter 140 carried by the station by exploiting the receiving capabilities of its acoustic communication device 203 preferably by measuring the phase difference of the signals received between at least three hydrophones.

[0272] 2. While approaching cable 130 of station 100, at one point Given, the image processing unit, its optical sensor, preferably its on-board camera 205, detects the presence of the cable 130, equipped or not with a light source 160 and then communicates to the computer of its control module the angular correction to be made to the heading of the AUV 200 so that it heads straight towards the cable 130 at the setpoint immersion.

[0273] 3. At the moment of the collision between the AUV 200 and the cable, a shock occurs. The cable then begins to slide along the port side 2011 or starboard side 2012 of the AUV, positioning it within the field of view of the optical sensors. As described previously with reference to the optional variants illustrated in Figures 3B and 3C, the AUV 200 can be guided by the guide device 242 to the housing 240 of the lashing device 210, which preferably forms a groove. Upon contact with the elastically articulated locking member 230, the cable enters the bottom of the housing 240. Once the constriction-forming opening 241 has been passed, the locking member 230 returns to its initial locking configuration and prevents the cable 130 from exiting the housing 240. The AUV 200 is thus permanently lashed to the cable 130.

[0274] 4. The AUV 200's propulsion system is then deactivated in order to limit fuel consumption The AUV's electric motor. Preferably, the AUV 200 exhibits negative buoyancy in fresh or salt water. By gravity, it then slides downwards along the cable until it encounters a stop, for example, a ballast or a locking ring.

[0275] The rallying operations of all the AUVs 200 continue according to the sequence of steps 1 to 3 described above.

[0276] Awaiting the vessel of opportunity for the replenishment of the storage stations

[0277] Once all 200 AUVs have reached the storage station(s), the entire storage system 1000 is in standby mode, awaiting the arrival of the recovery vessel 700, which will bring the storage stations 100 on board one after the other. This could also be an aircraft with a high lifting capacity, such as a helicopter or a drone.

[0278] The lifting of the storage stations 100 is similar to the hauling of lobster pots onto a fishing boat. It can be done manually or with the help of specific handling equipment 701 (cranes, hydraulic winches, etc.). This lifting is illustrated in [Fig. 9].

[0279] Use of the communication relay

[0280] According to an optional variant, the implementation of the 500 communication relay can be used for one or more of the following steps:

[0281] - Remotely monitor the progress of the rally stages. For this, the relay of The integrated 500 communication unit in the 170 buoy or in an SUV 300 uses its acoustic communication channel 502 to receive coded signals from the 200 AUVs that represent their progress, such as immersion depth and distance from the cable. Once decoded, this information is transmitted using the radio communication channel 503 and received on land or aboard a vessel.

[0282] - Guide the 700 recovery boat to the 100 storage station(s). To facilitate the guidance of the opportunity boat 700 to the storage station 100 to be retrieved, the radio communication channel of the relay 503 is used to transmit its GPS coordinates to the boat 700 which then guides itself towards the received position.

[0283] - Assist the guidance of the AUV 200 towards the cable 130 by a distance measurement.

[0284] In the case described above, the AUV 200 only knows the direction of Cable 130 rendezvous. Knowing the horizontal distance between the vessel and the cable can be useful, particularly for slowing down on approach for a smooth engagement or for detecting when it is moving away, which would necessitate a U-turn. To this end, the clock offset of the acoustic transmitter located on the cable from storage station 100 relative to the GPS time reference must be measured and this information transmitted to the AUVs 200. Subsequently, the difference between the TOA (Time of Arrival) of reception and the transmission time, multiplied by the average speed of sound in water, gives the distance between the AUV 200 and transmitter 140. This distance is then corrected for the difference in immersion between the AUV 200, known using its pressure sensor, and that of transmitter 140, measured along cable 130, to obtain a distance projected onto the horizontal plane.

[0285] Determination of the clock offset of the acoustic signal transmitter

[0286] The following paragraphs propose a method for determining the clock offset of the acoustic signal transmitter 140 carried by the storage station 100. The communication relay 500 is integrated into the body of the buoy 170.

[0287] The acoustic communication channel 175 detects the signal from the acoustic transmitter 140 of the storage station 100. It deduces a measured TOA, Tm, in the GPS time reference frame, the GPS time signal being delivered by the GPS receiver with an accuracy better than 10A-5 seconds.

[0288] It is then possible to calculate the emission time, Te, of said signal by applying the correction related to the propagation time of the signal in water. This propagation time is equal to the oblique distance, Do, separating the emitter 140 from the receiver of acoustic signals divided by the speed of sound in water.

[0289] The distance in the horizontal plane, Dh, is equal to the length of the link between the sub-surface float 120 and the buoy 170 possibly corrected for the immersion depth of the float 120.

[0290] The vertical distance, Dv, is equal to the difference in immersion between the hydrophone of the acoustic receiver 502 of the buoy 170 and that of the transmitter 140.

[0291] The average speed of sound in water, Cm, is determined by knowing the salinity and temperature of the water.

[0292] Do and Te are calculated using the following formulas:

[0293] Do= Square root ((Dh)A2 + (Dv)A2)

[0294] Te=Tm - ( Do / Cm )

[0295] Subsequently, the time difference between Te and the second round of the immediately lower satellite geolocation system will determine the clock offset of storage station 100. This value will be transmitted to the AUVs 200 using acoustic communication channel 502 of relay 500.

[0296] Variants

[0297] Several variants of the preceding examples will now be described. All these variants can be combined with the previously described features and with each other.

[0298] Use of the SUV

[0299] In this variant, the 500 communication relay is an integral part of an SUV 400 already present on site if required for the primary seabed exploration mission. The resulting advantage is having the simplest and least expensive possible storage station 100.

[0300] As illustrated in [Fig.1A], the SUV then presents a body 301 which forms the body 501 of the relay, as well as the components 502-506 described previously with reference to the communication relay 500.

[0301] Use of the current determination means

[0302] The means for determining the current, such as a current table based on the time of the tide, a drifting buoy, or a Doppler log fixed under a boat, is used to predict the strength and direction of the current at the scheduled arrival time of the AUVs 200. This arrival time can preferably be set at slack tide, or the mooring position of the storage station 100 can be adjusted so that the AUVs 200 reach the cable 130 facing the current. This makes the mooring of the AUVs 200 to the cable 130 even more reliable.

[0303] Use of a float 120 attached to the buoy 170

[0304] From the opportunity vessel, approaching storage station 100, the operator throws a grapple, aiming at the floating cable 181 separating the float 180 from the buoy 170. This speeds up the raising of storage station 100 and reduces the risk of seeing all or part of the device caught in the propeller or appendages of the boat of opportunity.

[0305] Variants concerning the mooring of storage stations.

[0306] In addition to the ballast 110, an anchor 111 and its chain can be provided when the storage station 100 is being put into the water to oppose the drift of the storage station 100 in the event of strong currents.

[0307] Moreover, as illustrated in [Fig.7] several ballasts 110a, 110b can be provided for the same storage station 100. For example, each of these ballasts 110a, 110b is linked to the cable 130 by a rope or a chain 1101a, 1101b.

[0308] In the example illustrated in [Fig. 8], the storage station 100 is configured so that the cable 130 is not positioned substantially vertically. The latter has an oblique direction or curvature relative to the vertical. For this purpose, at least two mooring devices (typically ballasts 110s, 110a, 110b) can be provided, spaced apart and each connected to the collection cable 130. One or more floats 120a, 120b, 120c are also provided, connected to the collection cable 130, to keep the latter away from the seabed 1.

[0309] In the illustrated example, the storage station 100 has two ground mooring devices 110, here two ballasts 110s 110a, 110b, and three floats 120a, 120b, 120c. The collection cable 130 then has a curved shape extending mainly in a horizontal direction. Locally, the collection cable 130 has varying extension directions Z130', Z130” along its length.

[0310] Alternatively, two mooring devices 110 on the ground and a single float 120 can be provided, for example located at an equal distance between the two mooring devices.

[0311] All the features described with reference to the storage stations mentioned above can be combined with this example.

[0312] This example with non-vertical cable has the advantage of limiting the maximum height H100 to which the storage station 100 rises from the seabed 1. This embodiment can prove useful when the water height is low or when underwater or surface activities prevent the deployment of a storage station 100 over a greater height.

[0313] In light of the foregoing description, it is clear that the invention makes it possible to considerably simplify the recovery of AUVs, in particular large fleets of AUVs. Furthermore, the storage system is particularly inexpensive, simple to transport and store.

[0314] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

Claims

1. Demands Set includes: - a plurality of autonomous underwater vehicles (AUVs) (200), each comprising at least one propulsion device (202), a control device configured to control the propulsion device (202) and an acoustic communication device (203) configured to receive acoustic signals, - an autonomous storage system (1000) for a plurality of autonomous underwater vehicles (AUVs) (200), the storage system (1000) comprising at least one storage station (100), characterized in that at least one storage station (100) comprises: • a collection cable (130) for the AUVs (200), • at least one mooring device (210) configured to moor the collection cable (130) to the seabed (1), and preferably comprising at least one ballast (110) intended to rest on a seabed (1), and • at least one float (120) exhibiting positive buoyancy in water and attached to the collection cable (130) such that the collection cable (130) extends between the float (120) and the mooring device, • an acoustic signal transmitter (140) connected to the collection cable (130) and configured to send acoustic signals to the AUVs acoustic communication device (200), and in that • Each AUV (200) includes at least one lashing device (210) configured to lay the AUV (200) to the cable, • For each AUV, the control device is configured to command the propulsion device, at least as a function of acoustic signals received from the transmitter (140), in order to bring the AUV (200) into a lashing configuration with the cable, the whole being configured so that the AUVs (200) of the plurality of AUVs (200) are lashed simultaneously to the collection cable (130).

2. Assembly according to the preceding claim, wherein the lashing device (210) and the cable are configured such that when the collection cable (130) is in contact with the lashing device (210), a displacement of the AUV (200) relative to the collection cable (130) triggers the locking of the cable in the lashing device (210).

3. An assembly according to any one of the preceding claims, wherein the lashing device (210) comprises a locking member (230) elastically articulated on the AUV, and the lashing device (210) and the collection cable (130) are configured such that: - when the collection cable (130) is in contact with the locking member (230), a displacement of the AUV (210), preferably rearward, relative to the collection cable (130) triggers a displacement of the locking member (230) to reach an open configuration in which it allows the collection cable (130) to access a housing (240) in the lashing device (210), - when the collection cable (130) has entered the housing (240), the locking member (230) elastically returns to a rest position, the locked configuration, in which it prevents the collection cable (130) to exit housing (240).

4. Assembly according to the preceding claim, wherein the locking member (230) is rotationally articulated on the AUV (200) so as to pivot to pass from the locking configuration to the opening configuration and vice versa.

5. Assembly according to the preceding claim, wherein this pivoting takes place around an axis substantially perpendicular to a straight-line (X200) forward direction of the AUV (200).

6. Assembly according to any one of the preceding claims, wherein the lashing device (210) is configured so that the AUV (200) lashes onto the collection cable (130) by a recoil movement of the AUV (200) relative to the collection cable (130).

7. Assembly according to the preceding claim, wherein the AUV (200) has two propulsion devices (202a, 202b) positioned on a rear portion (260) of the AUV (200), preferably symmetrically with respect to a median plane (ZX) of the AUV (200), and the docking device (210) is positioned between the two propulsion devices (202a, 202b).

8. Assembly according to any one of the two preceding claims, wherein the AUV (200) has two guide surfaces (270) each extending from the lashing device (210) and configured to guide the AUV (200) relative to the collection cable (130) towards the lashing device (210) during a recoil movement of the AUV (200).

9. Assembly according to any one of the three preceding claims, wherein the AUV (200) comprises at least one movable member (250), configured to adopt a deployed position (250a) when the AUV (200) is moving backward and to adopt a retracted position (250b) when the AUV (200) is moving forward, the movable member (250) being configured in the deployed position (250a) to guide the AUV (200) relative to the collection cable (130) toward the lashing device (210) during a backward movement of the AUV (200).

10. Assembly according to the preceding claim, wherein the transition from the deployed position (250a) to the retracted position (250b) is entirely ensured by a forward movement of the AUV (200) (X200) and the transition from the retracted position (250b) to the deployed position (250a) is entirely ensured by a backward movement of the AUV (200) (-X200).

11. Assembly according to any one of the two preceding claims, wherein the AUV (200) comprises two movable members (250) configured to together form an angle θ between 45° and 160° in the deployed position (250a, 250b) and to form together an angle o' between -20° and +20° in retracted position (250a', 250b').

12. Assembly according to any one of the preceding claims, wherein the AUV (200) includes a sensor configured to identify whether the collection cable (130) is blocked in the lashing device (210) and the AUV (200) is configured to transmit to a remote receiver, via its acoustic communication device, a signal indicating that the cable is blocked in the lashing device (210).

13. Assembly according to any one of the preceding claims, wherein the AUV (200) comprises a body (201), at least a front portion (206), a rear portion (260) and a side member (2011, 2012) extending between the front portion (206) and the rear portion (260), at least one lashing device (210) being located on at least one of the side member (2011, 2012) and the rear portion (260), the body (201) of the AUV (200) being shaped so that when the AUV (200) moves backward horizontally and in a straight line, the collection cable (130) is guided to the lashing device (210).

14. Assembly according to any one of the preceding claims, wherein the AUV (200) comprises two side walls (2011, 2012), and at least two lashing devices (210), each side wall (2011, 2012) being provided with at least one lashing device (210).

15. Assembly according to any one of the preceding claims, wherein the lashing device (210) is movably mounted on the body (201) of the AUV (200), with at least one degree of mobility.

16. Assembly according to the preceding claim, wherein the lashing device (210) is articulated on the AUV (200) by a linkage (281, 282, 283) comprising at least one degree of rotational freedom such as a pivot joint or a ball joint.

17. Assembly according to the preceding claim, wherein the lashing device (210) is linked to the AUV (200) by a deformable connection.

18. Assembly according to the preceding claim, wherein the lashing device (210) is configured to have a first configuration in which it is attached to the body (201) of the AUV (200) and a second configuration in which it is detached from the body (201) of the AUV (200) while remaining attached to the body (201) only by at least one link (287) preferably soft or flexible.

19. Assembly according to any one of the preceding claims, wherein the lashing device (210) and the collection cable (130) are configured such that in lashing configuration the AUV (200) retains a sliding degree of freedom relative to the collection cable (130) along a principal extension direction Z130 of the collection cable (130).

20. Assembly according to any one of the preceding claims, wherein the collection cable (130) includes at least one stop (150) configured to stop the downward sliding of the AUVs (200) under the effect of their gravity.

21. Assembly according to the preceding claim, wherein the collection cable (130) comprises a plurality of stops (150) distributed along the collection cable (130), the spacing between two stops (150) forming a lashing zone (1301-1304) for an AUV (200).

22. Assembly according to any one of the two preceding claims, wherein the distance DI50 separating two stops (150) is greater than the length L200 of an AUV (200), preferably D150>2*L200.

23. According to any one of the preceding claims, the AUV (200) comprises at least one optical sensor, the control device being configured to command the propulsion device (202), at least as a function of acoustic signals received from the transmitter (140) and optical data provided by the optical sensor, to bring the AUV (200) into the docking configuration with the collection cable (130).

24. Assembly according to any one of the preceding claims, wherein the collection cable (130) comprises visual coding elements, these visual coding elements comprise or form a sequence of several segments of a specific length, the sequence is configured so as to enable the AUV (200) to optically assess its distance to the collection cable (130) and / or to optically identify one or more docking zones assigned to the AUV (200).

25. Assembly according to the preceding claim, wherein the visual coding elements are taken from: light sources (160), retroluminescent elements, reflective elements.

26. Method of storing a plurality of AUVs (200) on at least one storage station (100) of an assembly according to any one of the preceding claims, the method comprising a phase of lashing the plurality of AUVs (200) to the submerged collection cable (130) of the storage station (100).

27. ​​A method according to the preceding claim, further comprising, prior to the docking phase, an installation step of the storage system (1000), the installation step comprising the immersion of the storage station (100) and the collection cable (130) being configured so that the float (120) is located below the surface of the water.

28. A method according to any one of the two preceding claims, wherein the storage station (100) is configured so that the collection cable (130) extends in the water in a substantially vertical direction.

29. Method for recovering a plurality of AUVs (200), comprising the steps of the storage method according to any one of the three preceding claims, and further comprising a step of raising, on the surface of the water, the collection cable (130) to which the plurality of AUVs (200) are attached and a step of recovering the AUVs (200) attached to the collection cable (130) by a ship or an aircraft, and preferably, the detachment of the AUVs (200) from the collection cable (130).

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