Underwater communication system and method

Abstract

The invention relates to an underwater communication system configured to transmit data between an underwater vehicle (100-1) and a remote device and / or another underwater vehicle (100-2), comprising a radiating cable (115) having a first end and a second end opposite the first end, a radiating cable immersion device attached to the first end of the radiating cable, a radiating cable guide attached to the second end of the radiating cable, a modem (120) connected to the radiating cable, a receive-transmit module (125) connected to the modem, with the modem and the receive-transmit module configured to transmit, as a guided signal through the radiating cable, data received by the receive-transmit module and / or to transmit, via the receive-transmit module, data obtained from a guided signal received from the radiating cable. (See Figure 3 for abbreviations.)

Description

Title of the invention: Underwater communication system and method. TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to an underwater communication system configured to transmit data between an underwater vehicle and a remote device and / or another underwater vehicle.

[0002] The invention further relates to a communication method for an underwater vehicle implemented in such a system. STATE OF THE ART

[0003] Underwater vehicles, with or without a pilot, for example underwater "drones" (or AUVs, abbreviation for Autonomous Underwater Vehicles in Anglo-Saxon terminology), are notably used to carry out underwater reconnaissance and surveillance missions, particularly of the seabed. These underwater vehicles or drones can operate individually or in flotillas.

[0004] These vehicles are equipped with sensors, for example sonars and / or cameras, to carry out measurements which are used to analyze an environment, for example the topography of a place, and / or to detect objects or detect abnormal situations such as a leak on a pipe.

[0005] For performance reasons, particularly autonomy, the analysis is often carried out in a remote device.

[0006] Although it is often not necessary to transmit raw data, i.e. unprocessed data from sensors, to a remote station in real time, an operational need may require periodic transmission of representative samples of captured data to begin an analysis before the end of the mission.

[0007] This can make it possible to check the proper functioning of the underwater drone, and / or to correct a mission, for example by modifying the trajectory of the underwater drone.

[0008] In certain circumstances, it may even be desirable to establish a high-speed communication link between the underwater drone(s) and one or more operational bases to interpret the measured data and, if necessary, adapt the ongoing mission. There may also be a need to share information between the underwater vehicles or drones to optimize the mission.

[0009] To achieve underwater communication between underwater vehicles or drones, or between an underwater vehicle or drone and a remote device, acoustic underwater communication systems using transmission are known. of an acoustic wave. These systems allow underwater communication over significant distances, up to several tens of kilometers, but they are sensitive to interference and may have limited performance for high-speed data transmission.

[0010] There are also electromagnetic communication solutions at very low frequency (also known as Very Low Frequency or VLF in Anglo-Saxon terminology) or extremely low frequency (also known as Extremely Low Frequency or ELF in Anglo-Saxon terminology) allowing communication between underwater devices.

[0011] Communication systems using WiFi™ technology are also known, as described, for example, in the document entitled “Contactless data transfer for autonomous underwater vehicle docking station”, PJ Bouvet et al., OCEANS 2021, Sept. 2021, San Diego, CA, USA; as well as inductive or even optical communication systems.

[0012] These known systems can be complex and exhibit very limited, or even random, performance over long distances, leading to very low data rates, on the order of a few tens of bits per second, which generally do not allow sufficiently fast transmission of data and / or commands.

[0013] Furthermore, when vehicles or underwater drones of a flotilla need to exchange data with each other and / or with a remote device, communications can be even more difficult. Description of the invention

[0014] The present invention aims to provide an underwater communication system, of a type similar to those described above, which is particularly efficient for establishing easy, fast and high-speed communication between underwater vehicles or drones and / or between underwater vehicles or drones and remote stations, while being convenient in its use and economical.

[0015] To this end, the invention relates to an underwater communication system configured to transmit data between an underwater vehicle and a remote device and / or another underwater vehicle, the communication system comprising a radiating cable having a first end and a second end opposite the first end, a device for immersing the radiating cable, in particular a float or an aerial drone, attached to the first end of the radiating cable and configured to submerge the radiating cable, a guiding element for the radiating cable, in particular a weight, attached to the second end of the radiating cable and configured to tension the radiating cable at the second end, a modem connected to the radiating cable, a receive-transmit module connected to the modem, with the modem and the receive-transmit module which are configured to transmit, as a guided signal through the radiating cable, data received by the receive-transmit module and / or to transmit, via the receive-transmit module, data obtained from a guided signal received from the radiating cable.

[0016] Such an underwater communication system makes it possible to establish easy, fast, unidirectional or bidirectional and high-speed communication between underwater vehicles or drones and / or between underwater vehicles or drones and remote stations, while being convenient in its use and economical in both manufacture and installation.

[0017] Indeed, the inventors determined that the use of such a radiating cable (also known as a leaky cable, radiating cable or leaky feeders in Anglo-Saxon terminology), generally used in tunnels to maintain a radio connection between a mobile device located inside a tunnel and an external device, enabled the establishment of fast and high-speed communication between underwater vehicles or drones and / or between underwater vehicles or drones and remote stations.

[0018] Preferred, simple, convenient and economical features of the underwater communication system according to the invention are presented below.

[0019] The underwater communication system may further include at least one positioning stop arranged between the first end and the second end of the radiating cable and configured to receive support from at least one underwater vehicle.

[0020] The receive-transmit module can be fixed on the immersion device of the radiating cable.

[0021] The receive-transmit module can be mounted in a cavity of the radiating cable immersion device.

[0022] The modem can be mounted in the cavity of the radiating cable immersion device and directly connected to the receive-transmit module.

[0023] The modem can be fixed to the first end of the radiating cable and configured to be submerged with the radiating cable, the underwater communication system further comprising a communication cable connecting the modem and the receive-transmit module and being configured to be at least partially submerged.

[0024] The receive-transmit module may include a transceiver.

[0025] The underwater communication system may include a support cable configured to support at least the radiating cable.

[0026] The invention also relates, according to a second aspect, to a communication method for an underwater vehicle implemented in an underwater communication system marine as described above, the process includes the steps of detecting a radiating cable, moving the underwater vehicle towards the radiating cable, and exchanging data via the radiating cable.

[0027] The method may include the step of attaching the underwater vehicle to the radiating cable. BRIEF DESCRIPTION OF THE FIGURES

[0028] The invention, according to an exemplary embodiment, will be well understood and its advantages will become more apparent upon reading the detailed description that follows, given by way of example and in no way limiting, with reference to the attached drawings.

[0029] Fig. 1 represents an underwater communication system configured to transmit data between an underwater vehicle and a remote device, according to one embodiment of the invention.

[0030] Figure 2 schematically illustrates a section of a radiating cable that can be used in an underwater communication system according to the invention.

[0031] Figures [Fig. 3], [Fig. 4], and [Fig. 5] schematically illustrate a system of underwater communication configured to transmit data between one or more underwater vehicles and / or with a remote device, according to different embodiments of the invention.

[0032] Figure 6 is a block diagram showing an example of steps implemented in an underwater vehicle to exchange data in an underwater communication system illustrated in figures 1 and 3 to 5. DETAILED DESCRIPTION OF THE INVENTION

[0033] Fig. 1 represents an underwater communication system configured to transmit data between an underwater vehicle 100, such as an underwater drone, and a remote device which is here a surface vessel 105.

[0034] The submarine communication system includes a radiating cable 115 having a first end and a second end opposite to the first end.

[0035] The submarine communication system includes a 120 modem (modulator-demodulator) connected to the radiating cable 115.

[0036] In particular, the modem 120 is fixed and connected to the first end of the radiating cable 115 and configured to be immersed with the radiating cable 115.

[0037] The underwater communication system includes a receive-transmit module 125 connected to the modem 120. In particular, the receive-transmit module 125 here includes a transceiver.

[0038] The submarine communication system further includes a communication cable 130 connected to the modem 120 and the receive-transmit module 125.

[0039] In other words, the modem 120 is connected in the illustrated example to the receive-transmit module 125 via the communication cable 130.

[0040] Alternatively, the underwater communication system may be devoid of a communication cable, the modem being for example directly connected to the receive-transmit module.

[0041] The underwater vehicle 100 can here exchange data with the surface vessel 105.

[0042] For these purposes, the underwater vehicle 100 is equipped with a modem (modulator-demodulator) 110 connected to an antenna (not shown) to receive and transmit data via the radiating cable 115 itself connected to the modem 120.

[0043] The radiating cable 115 can be seen as a very long antenna capable of transforming a guided signal into a radiating signal, and vice versa.

[0044] Data can then be exchanged between the receive-transmit module 125 and a transceiver installed on the surface vessel 105 and connected to an information system (also called an information processing system), for example using standard wireless communication technologies.

[0045] Similarly, the receive-transmit module 125 can exchange data with a terrestrial information system, for example using satellite communication.

[0046] In one embodiment, when communication needs to be established deep underwater with a submersible vehicle to exchange data with a remote device, for example a surface vehicle 105 or a land station, the communication cable 130 makes it possible to limit the length of the radiating cable 115, the latter being more sensitive to interference than the communication cable 130.

[0047] The underwater communication system includes a radiating cable immersion device, fixed to the first end of the radiating cable 115 and configured to immerse the radiating cable 115.

[0048] The immersion device of the radiating cable 115 is here formed by a float (also called a buoy) 135.

[0049] In the illustrated example, the receive-transmit module 125 is fixed to the float 135 or mounted in a cavity of the latter.

[0050] In other words, the modem 120 is arranged here at a distance from the receive-transmit module 125 and the float 135.

[0051] Alternatively, the modem can be fixed to the float or housed in a cavity in it.

[0052] The underwater communication system includes a radiating cable guide element 115 fixed to the second end of the radiating cable 115 and configured to tension the radiating cable 115 from the second end.

[0053] The guiding element is here formed by a ballast 140.

[0054] The submarine communication system herein further includes a support cable (not shown) configured to support at least one of the radiating cable 115, the modem 120 and the communication cable 130.

[0055] An upper part of the support cable can be attached to the float 135 and a lower part of the support cable can be attached to the ballast 140.

[0056] In other words, the ballast 140 plays a guiding role (in particular by gravity) of the radiating cable 115 and / or the support cable.

[0057] The radiating cable 115 can thus be stretched vertically in line with the float 135, facilitating its approach by the underwater vehicle 100.

[0058] It should be noted that the radiating cable and / or the communication cable can also be support cables, provided for example with a reinforcement structure.

[0059] For example, the modem 110 equipping the underwater vehicle 100 is positioned at the front of the latter, the front of the underwater vehicle 100 being further provided with cable detection means and attachment means, as described for example in patent application EP 3 197 768.

[0060] To enable the underwater vehicle 100 to avoid having to control its position when it is attached to the radiating cable 115 (or the support cable supporting it), the radiating cable 115, or the support cable, can be equipped with a stop 145 arranged between the first end and the second end of the radiating cable 115, on which the underwater vehicle 100 can rest.

[0061] When attached to the radiating cable 115, or to the support cable supporting it, the underwater vehicle 100 can transmit data, for example data from one or more sensors 150 such as a sonar, or receive data, for example mission data, via the radiating cable 115.

[0062] The float 135 can be used to perform several functions. In particular, it can secure an underwater vehicle if recovery is impossible, for example, due to sea conditions, a breakdown of the carrier vessel, or if the recovery date cannot be determined (especially if the carrier vessel is unavailable). It can also secure recovery operations during long-duration operations and establish intermediate recovery points, for example, due to insufficient range or a change in mission. Furthermore, it can maintain an underwater vehicle, whether heavy or light, at a safe depth relative to surface vessels. A vehicle The submarine can remain securely attached (also called "docked") to an underwater communication system.

[0063] The float 135 may further include location means and transmit location information to an underwater vehicle to improve the navigation of the latter.

[0064] Furthermore, the float 135 can be used to signal the presence of one or more underwater vehicles in maritime traffic.

[0065] An access point can also be used to enable communication between several underwater vehicles, each underwater vehicle establishing a communication channel with the access point.

[0066] The access point, for example of the WiFi™ type or conforming to the IEEE 802.11 standard, can in particular be associated with the receive-transmit module 125 and be integrated into the float 135.

[0067] Fig. 2 schematically illustrates a section of a radiating cable that can be used in an underwater communication system according to the invention.

[0068] The radiating cable 115 is here a coaxial cable comprising a transmission line formed of a conductive core 200 and a shield formed using an outer conductive layer 205.

[0069] The conductive core and the shielding are isolated from each other by a dielectric 210.

[0070] The radiating cable 115 is protected by an outer sheath 215.

[0071] For example, the central core can be made of copper or copper-based material and be single-strand or multi-strand.

[0072] The shielding can, for example, be made from a copper braid.

[0073] The outer conductive layer 205 includes a set of referenced openings 220 through which part of the energy carried by the conductive core can be evacuated in the form of radiation, or through which part of an external radiation can be received by the conductive core.

[0074] The arrangement of the openings, for example regularly provided on the radiating cable, and their geometries are chosen according to the required characteristics, in particular in terms of transmission / reception power, in terms of transmission / reception orientation with respect to the presence of an underwater vehicle, etc.

[0075] These characteristics can vary depending on the sections of the radiating cable and the openings can then be arranged by groups and / or by sections.

[0076] When the radiating cable, or the support cable, includes one or more stops, the position of the openings made in the outer conductive layer 205 is preferably determined according to the position of these stops.

[0077] Fig. 3 schematically illustrates an example of an underwater communication system between two underwater vehicles, for example two underwater drones, and between an underwater vehicle and a remote device.

[0078] The submarine communication system includes such a radiating cable 115 enabling the establishment of high-speed communication over short distances and which is connected to the modem 120, itself connected to the receive-transmit module 125 via the communication cable 130.

[0079] The modem 120 allows a guided signal that is received through the radiating cable 115 to be demodulated into a signal that can be transmitted by the receive-transmit module 125.

[0080] The modem 120 also allows a signal received via the receiver-transmitter module 125 to be modulated into a guided signal transmitted by the radiating cable 115, this guided signal being transformed into a radiating signal, i.e. causing the emission of a radio signal via the openings made in the radiating cable 115.

[0081] To exchange data through the radiating cable 115, an underwater vehicle 100-1, for example an underwater drone, includes an antenna 300-1 connected to a modem 110-1, itself connected to a communication bus to which can also be connected, for example, a microprocessor 305-1 (or CPU for Central Processing Unit in Anglo-Saxon terminology), one or more memory units 310-1 and one or more input / output units 315-1.

[0082] The memory unit(s) 310-1 are, for example, of type read-only memory (or ROM for Read Only Memory in Anglo-Saxon terminology), random access memory (or RAM for Random Access Memory in Anglo-Saxon terminology) and / or mass storage (for example of type SSD for Solid State Device in Anglo-Saxon terminology).

[0083] The input / output unit(s) can in particular be connected to one or more sensors 320-1 and / or one or more actuators 325-1.

[0084] The modem 110-1 allows demodulation of a signal received from the antenna 300-1 into a signal that can be processed by the microprocessor 305-1. The modem 110-1 also allows modulation of a signal received from the microprocessor 305-1 into a signal that is then transmitted by the antenna 300-1 as a radiated signal.

[0085] The memory unit(s) 310-1 can store instructions in the form of a computer program. These instructions are interpreted by the microprocessor 305-1 to implement one or more processes in the underwater vehicle 100-1, for example to pilot it, acquire data and / or process acquired and / or received data.

[0086] Alternatively or in addition, a programmable electronic chip, such as an FPGA chip (for Field-Programmable Gate Array in Anglo- Saxon), a SoC (for System On Chip in Anglo-Saxon terminology), a GPU (for Graphics Processing Unit in Anglo-Saxon terminology), or an ASIC (for Application Specified Integrated Circuit in Anglo-Saxon terminology) can be used.

[0087] SoCs or system-on-chip are embedded systems that integrate all the components of an electronic system into a single chip.

[0088] An ASIC is a specialized electronic circuit that combines features tailored to a specific application. ASICs are generally configured during manufacturing and can only be simulated by the user.

[0089] FPGA type programmable logic circuits are electronic circuits that can be reconfigured by a user.

[0090] The underwater vehicle 100-1 can thus transmit data to another underwater vehicle 100-2 and / or to a remote device (not shown) via the radiating cable 115, the modem 120 and the receive-transmit module 125 which can act as an access point.

[0091] The underwater vehicle 100-1 can also receive data from the underwater vehicle 100-2 and / or from this remote device.

[0092] Figure 4 illustrates an underwater communication system configured to transmit data between underwater vehicles and a remote device.

[0093] The underwater communication system here allows data exchanges between a first underwater vehicle 100-1 and a remote device, between a second underwater vehicle 100-2 and the remote device, and between the first underwater vehicle 100-1 and the second underwater vehicle 100-2.

[0094] The first underwater vehicle 100-1 and the second underwater vehicle 100-2 are each equipped with an antenna and a modem (not shown), and the remote device is equipped with a transceiver (not shown).

[0095] In the illustrated example, the first underwater vehicle 100-1 and the second underwater vehicle 100-2 are underwater drones, while the remote device here is a surface vessel 105.

[0096] The underwater communication system includes a radiating cable 115 which is directly connected, at the first end, to a float 135' which includes a modem and a receive-transmit module (not shown).

[0097] The second end of the radiating cable 115 is fixed to a weight 140 which plays a guiding role, in particular by gravity, of the radiating cable.

[0098] The underwater communication system further includes a set of positioning stops, here four positioning stops referenced 145-1 to 145-4, allowing underwater vehicles to come into support.

[0099] The radiating cable 115 advantageously includes a reinforcing structure and / or is associated with a support cable to support the various elements.

[0100] Fig. 5 illustrates another underwater communication system for exchanging data between an underwater vehicle 100, such as an underwater drone, and a remote device.

[0101] In the illustrated example, the remote device is the radiating cable immersion device 115, which here is an aerial vehicle 600, in particular an aerial drone or a helicopter.

[0102] The underwater communication system includes a radiating cable 115 which is connected, at the first end, to a modem 120 which is itself connected, via the communication cable 130, to a receive-transmit module (not shown) of the aerial drone 600.

[0103] The second end of the radiating cable 115 is fixed to a weight 140 which plays a guiding role for the radiating cable 115, in particular by gravity and due to the speed of movement of the aerial drone 600.

[0104] The underwater communication system further includes a set of positioning stops, here two positioning stops referenced 145-1 and 145-2, allowing underwater vehicles to come into support.

[0105] The modem 120 enables the aerial drone 600's receive-transmit module to receive data transmitted via the radiating cable 115 in the form of a guided signal and to transmit data in the form of a guided signal via the radiating cable 115 to enable the transmission of a corresponding radio signal.

[0106] The radiating cable 115 and / or the communication cable 130 include, for example, a reinforcement structure and / or are associated with a support cable to support the various elements.

[0107] In unillustrated embodiments, the antenna of an underwater vehicle is positioned substantially on one side of the underwater vehicle, which is equipped with attachment devices configured to attach to the radiating cable to communicate with a remote device, without using dynamic positioning means to maintain a particular position relative to the radiating cable. For example, a torpedo-shaped AUV (Autonomous Underwater Vehicle) can position itself vertically to communicate with a vertically oriented radiating cable.

[0108] Figure 6 illustrates an example of steps implemented in an underwater vehicle, such as an underwater drone, to exchange data via an underwater communication system as described above with reference to Figures 1 and 3 to 5.

[0109] Figure 6 therefore illustrates a communication method comprising a step of detecting a radiating cable, for example using sonar, and of controlling actuators to move the underwater vehicle in the direction of the radiating cable (step 800). This step aims to bring the communication antenna of the underwater vehicle (for example the 300-1 antenna illustrated in [Fig.3]) close to the radiating cable, for example to a distance of less than 50 cm, preferably a distance of less than 10 cm.

[0110] The method includes an optional step of attaching the underwater vehicle to the radiating cable or to an associated support cable (step 805), for example using a mechanism such as that described in patent EP 2 551 185.

[0111] The attachment step may also include a stop. For example, the attachment system may allow the underwater vehicle to slide along the radiating cable or the associated support cable to come to a stop due to its weight, its movement or the movement of the radiating cable.

[0112] When the underwater vehicle is near or attached to the radiating cable, it can then communicate with a remote device via the communication cable (step 810). This communication can be established using a standard wireless communication protocol, for example conforming to the WiFi™ or IEEE 802.11 communication standard, or a specific wireless communication protocol.

[0113] After all the data to be transmitted has been transmitted and / or all the data to be received has been received, the communication is terminated.

[0114] When communication is complete, i.e. at the end of data exchange or in case of a problem, the underwater vehicle can move away from the radiating cable, after detaching itself from it (step 815) if it was attached to it.

[0115] The steps illustrated in [Fig.6] can for example be implemented using the elements 110-1 and 300-1 to 325-2 illustrated in [Fig.3].

[0116] It should be noted that, depending on the embodiment, certain acts, actions, events, or functions of each of the methods described in this document may be performed or occur in a different order than described, or may be added, merged, or not performed or occur, as the case may be. Furthermore, in some embodiments, certain acts, actions, or events are performed or occur concurrently rather than sequentially.

[0117] More generally, the invention is not limited to the examples described and shown.

Claims

Demands

1. Underwater communication system configured to transmit data between an underwater vehicle (100, 100-1) and a remote device and / or another underwater vehicle (100-2), the communication system comprising a radiating cable (115) having a first end and a second end opposite the first end, a radiating cable immersion device formed by a float (135, 135') or an aerial vehicle (600), attached to the first end of the radiating cable and configured to immerse the radiating cable, a radiating cable guidance element formed by a ballast (140), attached to the second end of the radiating cable and configured to tension the radiating cable from the second end, a modem (120) connected to the radiating cable, a receive-transmit module (125) connected to the modem, with the modem and the receive-transmit module configured to transmit,in the form of a signal guided through the radiating cable, data received by the receive-transmit module and / or to transmit, via the receive-transmit module, data obtained from a guided signal received from the radiating cable.

2. System according to claim 1, further comprising at least one positioning stop (145-1,145-2,145-3,145-4) arranged between the first end and the second end of the radiating cable and configured to receive at least one underwater vehicle as a support.

3. System according to any one of claims 1 and 2, wherein the receive-transmit module is fixed on the radiating cable immersion device.

4. System according to any one of claims 1 and 2, wherein the receive-transmit module is mounted in a cavity of the radiating cable immersion device.

5. System according to claim 4, wherein the modem is mounted in the cavity of the radiating cable immersion device and directly connected to the receive-transmit module.

6. A system according to any one of claims 3 and 4, wherein the modem is fixed to the first end of the radiating cable and configured to be immersed with the radiating cable, the communication system underwater further comprising a communication cable (130) connecting the modem and the receive-transmit module and being configured to be at least partially submerged.

7. System according to any one of claims 1 to 6, wherein the receive-transmit module comprises a transceiver.

8. System according to any one of claims 1 to 7, further comprising a support cable configured to support at least the radiating cable.

9. A communication method for an underwater vehicle, implemented in an underwater communication system according to any one of claims 1 to 8, the method comprising a detection (800) of the radiating cable, a movement of the underwater vehicle towards the radiating cable, and an exchange (810) of data via the radiating cable.

10. Method according to claim 9, further comprising an attachment (805) of the underwater vehicle to the radiating cable.

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