Righting device for an underwater vehicle

Abstract

The invention relates to an autonomous underwater vehicle (1, 30, 50, 80), which comprises a hull (3, 40, 60, 86) extending along a longitudinal main axis (5, 38, 58, 99), and at least one vehicle uprighting device configured to alter a trim angle of the vehicle (1, 30, 50, 80) between a nominal horizontal position of the vehicle and a vertical position of the vehicle, characterised in that the vehicle uprighting device comprises one or more arms (24, 26, 32, 52, 62, 92) mounted on the hull (3, 40, 60, 86) by a proximal end (24a, 26a) and rotatably hinged to the hull (3, 40, 60, 86), and comprising a float (28, 29, 34, 54, 64, 90) at a distal free end (24b, 26b).

Description

[0001] TITLE: Verticalizing device for underwater vehicle

[0002] Technical field of the invention

[0003] The present invention relates to underwater vehicles, in particular autonomous underwater vehicles, better known by the acronym AUV meaning Autonomous Underwater Vehicle.

[0004] In particular, the invention relates to a system making it possible to vary the attitude angle of such an AUV, in particular to put it in a vertical or close to vertical position. State of the art

[0005] AUVs are generally designed to navigate in a nominal horizontal position in the water. In this nominal position, the AUV has a zero or near-zero trim angle and is in a so-called equilibrium position in the water. Its trim angle is defined by the angle between its longitudinal axis and a horizontal plane. Navigating in a nominal horizontal position reduces drag forces and minimizes energy consumption during navigation.

[0006] A change in attitude angle to get closer to the vertical of the AUV may be required to carry out certain operations, including monitoring sites using cameras fitted to the AUV, or resetting the navigation system using the AUV's antennas placed out of the water, or simply for the recovery of the AUV.

[0007] Various devices are known for changing the attitude angle of an AUV. One such device is a propulsion system, comprising one or more thrusters, mounted on the AUV and operated to change the attitude angle of the AUV.

[0008] This is particularly possible when the propulsion system has one of the following configurations: - One or more vertical thrusters (for example, one at the front and one at the rear of the vehicle). Thus, the opposing thrusts of the thrusters induce a modification of the trim angle of the vehicle; - Horizontal thrusters located far from the main longitudinal axis of the vehicle. Thus, the opposing thrusts of the thrusters induce a torque on the vehicle, which modifies the trim angle of the vehicle;

[0009] - One or more steerable thrusters, so that by changing the orientation of the thrusters and therefore the thrust, the vehicle's trim angle can be changed.

[0010] Another of these devices is formed by so-called adjustment boxes housed at the front and rear of the AUV. Each adjustment box defines a volume and is at least partially filled with fluids. The quantities of fluids vary in the different boxes to vary the trim angle of the AUV.

[0011] Thrusters and trim boxes can also be simultaneously integrated into an AUV to increase trim capabilities. Disclosure of the invention

[0012] The invention aims to provide an autonomous underwater vehicle comprising a vertical positioning device which is particularly simple and convenient, both in its manufacture and in its use.

[0013] The invention thus relates, in a first aspect, to an autonomous underwater vehicle comprising a hull extending along a main longitudinal axis, at least one device for verticalizing the vehicle configured to modify a trim angle of the vehicle between a nominal horizontal position of the vehicle and a vertical position of the vehicle, characterized in that the device for verticalizing the vehicle comprises one or more arms mounted by a proximal end on the hull and articulated in rotation relative to the hull, and comprising a float at a distal free end so that the arm is configured to take:

[0014] - a folded position when the vehicle is in the nominal position with a trim angle of substantially zero, in which the arm is substantially parallel to the main longitudinal axis of the vehicle and the float is in the immediate vicinity of the hull; - a deployed position in which the arm is inclined relative to the main longitudinal axis so as to bring and / or stabilize the vehicle into a so-called vertical position with a trim angle greater than 70° relative to its nominal position. In the autonomous underwater vehicle according to the invention, the articulated arm makes it possible to move the float away from the hull of the vehicle and, due to the buoyancy of the float, this makes it possible to modify the position of the center of volume of the vehicle, also called the center of buoyancy or thrust, in order to facilitate the verticalization of the vehicle. Deployment of the arm requires only very little energy, which is advantageous for autonomous vehicles.In addition to being convenient, the addition of such an arm equipped with a float is a compact solution since it changes very little to the architecture of the autonomous underwater vehicle.

[0015] According to one embodiment, the autonomous underwater vehicle may comprise at least two arms, fixed to the hull on the port and starboard sides, arranged so as to form an angle between them in the range [60°; 180°[.

[0016] The autonomous underwater vehicle may include at least one actuating member enabling the arm to move from the stowed position to the deployed position. The actuating member may further enable the arm to move from the deployed position to the stowed position.

[0017] Alternatively, only irreversible deployment of the arm is possible.

[0018] According to one embodiment, the actuating member is capable of orienting the arm in a determined or selected angular position relative to the main longitudinal axis.

[0019] According to one embodiment, the actuating member can be configured to adapt, depending on the attitude angle of the vehicle, the angular position of the arm in the deployed position, relative to the main longitudinal axis.

[0020] According to one embodiment, the autonomous underwater vehicle may include a verticality sensor, such as an accelerometer, such that the angular position of the arm is monitored and controlled based on the output signal of the verticality sensor. This ensures stability of the AUV in its vertical or near-vertical position, even in the event of disturbances related to the environment, and in particular the effects of waves or the density of the water.

[0021] According to one embodiment, the float may have a variable volume. This may influence the position of the center of thrust and therefore may also improve the stability of the AUV in its vertical or near-vertical position.

[0022] According to one embodiment, at least one of the arms can be telescopic. This makes it possible to adjust a distance between the distal end and the proximal end of the arm, so as to move the floats closer to or further away from the hull of the vehicle. It is possible to facilitate the verticalization of the vehicle. This distance can also be monitored and controlled using a verticality sensor.

[0023] According to one embodiment, the autonomous underwater vehicle may additionally comprise one or more adjustment boxes capable of varying the trim angle of the vehicle.

[0024] According to one embodiment, the autonomous underwater vehicle may additionally comprise one or more thrusters capable of varying the trim angle of the vehicle.

[0025] The combination of the arm and the adjustment boxes and / or the thrusters makes it possible to further facilitate the verticalization of the autonomous underwater vehicle. In particular, the adjustment boxes and / or the thrusters make it possible to initiate the verticalization of the autonomous underwater vehicle, and when the trim angle reaches a threshold value, the arm can be deployed so as to finalize the verticalization and ensure the stability of the vehicle, once the vehicle is verticalized.

[0026] According to one embodiment, the adjustment boxes can be arranged, when the vehicle is in nominal position, in an upper part of the hull and the arms are attached to a lower part of the hull of the vehicle.

[0027] The invention relates, according to a second aspect, to a method for placing a vehicle as mentioned above in a vertical position, comprising actuating the arm to place it in the deployed position, from the folded position, in particular when the trim angle of the vehicle reaches a first threshold angle.

[0028] According to one embodiment, the method may comprise first initiating the verticalization of the vehicle by means of adjustment boxes and / or thrusters.

[0029] According to one embodiment, the method may comprise actuating the arm to place it in the stowed position from the deployed position when the trim angle of the vehicle is less than a second threshold angle.

[0030] Other features and advantages of the invention will become apparent in the description below.

[0031] Brief description of the figures

[0032] The invention, according to several exemplary embodiments, will be well understood and its advantages will appear better on reading the detailed description which follows, given for information purposes and in no way limiting, with reference to the appended drawings in which:

[0033] Figure 1 illustrates an autonomous underwater vehicle according to the invention.

[0034] Figure 2 illustrates an autonomous underwater vehicle according to the invention whose vertical positioning is initiated.

[0035] Figures 3A and 3B illustrate a first embodiment of the invention, showing an AUV having an arm in a folded position.

[0036] Figures 4A and 4B illustrate the first embodiment of the invention, in which the arm is in the deployed position.

[0037] Figures 5A and 5B illustrate a second embodiment of the invention, showing an AUV having two arms in a folded position.

[0038] Figures 6A and 6B illustrate the second embodiment of the invention, in which the arms of the vehicle are in the deployed position.

[0039] Figures 7, 8 and 9 illustrate a third embodiment showing an AUV having control boxes in addition to arms.

[0040] Figure 10 illustrates examples of different positions of the arms of the third embodiment. Detailed description

[0041] Identical elements shown in the above figures are identified by identical reference numerals.

[0042] The invention finds an application in the field of autonomous underwater vehicles, intended to be used once or several times, following their recovery in the open sea.

[0043] The invention applies in particular to vehicles known under the term AUV, as described above.

[0044] In general, autonomous underwater vehicles are used to carry out various operations at sea, such as surveillance operations.

[0045] For this purpose, autonomous underwater vehicles are launched from a boat (such as USVs, Unmanned Surface Vessels) or a submarine, or even an aircraft, and navigate completely submerged in the water in a nominal position close to horizontal.

[0046] An example of an autonomous underwater vehicle 1 navigating at sea 15 is thus illustrated in FIG. 1. In the remainder of the description, the terms vehicle and autonomous underwater vehicle are used interchangeably to designate an autonomous underwater vehicle. The autonomous underwater vehicle 1 comprises a hull 3, of cylindrical shape or not. In certain embodiments, the underwater vehicle may be of any other shape. This hull extends along a main longitudinal axis 5. In the example illustrated, the main longitudinal axis 5 passes through the nose 21 of the autonomous underwater vehicle 1 and a propulsion system 11, such as propeller thrusters for example.

[0047] The vehicle 1 is illustrated in Figure 1 in the nominal navigation position, in which the main longitudinal axis 5 is substantially parallel to the horizontal axis. In the remainder of the description, by horizontal plane is meant a plane having an orientation parallel to the horizon. In the nominal navigation position, the hull 3 comprises an upper part 3a facing the surface of the sea 15, and a lower part 3b facing the seabed 17. In order to limit as much as possible the effect of drag forces, in general, during the nominal navigation of the vehicle (apart from operations requiring maneuvers of the change of orientation type), the vehicle is configured to navigate in the nominal position illustrated in Figure 1, that is to say in which the main longitudinal axis 5 forms a zero or almost zero angle with the horizontal plane. For example, the angle formed is an angle between 0° and 10°.This angle, hereinafter called the trim angle, is the longitudinal inclination of the vehicle 1, that is to say the trim angle formed by the main longitudinal axis 5 with the horizontal plane 19 (parallel to the direction 23a of the reference frame 23).

[0048] To enable the autonomous underwater vehicle to be maneuvered underwater, the underwater vehicle must neither rise nor fall in its nominal position, which means that the vehicle must have a zero or almost zero trim angle in the equilibrium position. The nominal position of vehicle 1 is an equilibrium position of vehicle 1 when it is submerged, and depends in particular on the relative position of the center of gravity and the center of thrust, also called the center of buoyancy or volume. When the forward speed of the vehicle is zero, the nominal position of the vehicle, for a vehicle with zero buoyancy, is characterized by the fact that the center of gravity and the center of thrust are aligned along the vertical (direction 23b orthogonal to the horizontal plane 19).

[0049] The center of gravity of the vehicle 1 depends on its architecture, that is, on the mass distribution of its body and the elements it contains inside the hull. The center of thrust of the vehicle, the place on the vehicle where the hydrostatic forces, "Archimedes' thrust", are applied, varies according to the distribution of volumes in the vehicle.

[0050] The equilibrium position may vary when the vehicle 1 is maneuvered, in particular when the speed of the vehicle 1 is modified, due to the influence of hydrodynamic forces. Also, it appears necessary to modify this equilibrium position of the vehicle to carry out operations requiring maneuvers of the orientation change type, such as verticalization, as illustrated in Figure 2, described below.

[0051] The vehicle 1 therefore includes elements making it possible in particular to manage the relative position of the center of gravity and the center of thrust in order to modify the equilibrium position of the vehicle 1 for carrying out the various maneuvers. In other words, this amounts to modifying the attitude angle of the vehicle 1.

[0052] As previously indicated, the underwater vehicle 1 here comprises a thruster 11 arranged at one end of the hull 3 of the vehicle and which is capable of modifying the speed of movement of the vehicle underwater and also of maneuvering the vehicle. Maneuvering the underwater vehicle means allowing its movement in the three directions identified 23a, 23b, 23c by the reference frame 23 shown in FIG. 1.

[0053] The thrust applied to the vehicle 1 by the thruster 11 then drives the vehicle 1 with the part 21, called the nose, ahead of the rest of the vehicle 1. In the illustrated example, the nose 21 and the thruster 11 are aligned along the longitudinal main axis 5 of the vehicle 1.

[0054] In addition to the propellant 11, the vehicle 1 comprises control boxes 7, 9 respectively arranged at the front and rear of the vehicle 1. These are boxes 7, 9 defining a volume, partially filled with a liquid, such as water or oil. The volume of liquid contained in the control boxes 7, 9 can be modified, so as to vary the center of thrust of the vehicle 1, thus making it possible to vary the trim angle of the vehicle 1. In the example illustrated, the control boxes 7, 9 are connected to each other by a pipe, thus forming a closed circuit.

[0055] Alternatively, the control boxes can admit liquid (for example sea water) from the outside or discharge liquid to the outside. The admission of sea water, to weigh down the control boxes, can be done by means of a tap coupled with a flow limiter (in particular in the event of overpressure outside the vehicle). The evacuation of water from the control boxes can be done by means of a pump advantageously coupled with a non-return valve. This variation of the overall volume of liquid in the control boxes makes it possible to vary the weight of the vehicle in the water. This makes it possible to move the vehicle closer to or further from the surface.

[0056] The variation of the volume contained in the adjustment boxes 7, 9 makes it possible to modify the position of the center of thrust by modifying the distribution of weight inside the hull 3 of the vehicle.

[0057] These boxes are generally arranged at the front and rear of the vehicle 1. Of course, the vehicle 1 may include several other adjustment boxes 7, 9, arranged differently (to starboard and to port for example). Thus, as mentioned previously, the thrusters and the adjustment boxes can be used (whatever their positions) to initiate the verticalization of the vehicle 1, as illustrated in Figure 2.

[0058] Figure 2 illustrates an example of an operation for monitoring an area of ​​interest 13, requiring the vehicle 1 to be placed in a “permanent” vertical position. The so-called “permanent” vertical position, i.e. for a desired determined duration, of a vehicle 1 proves to be an operational asset when using the vehicle 1 and in particular when using the on-board sensors of the vehicle 1.

[0059] Indeed, the use of the sensors is less impacted by the swell when the AUV is in a vertical position rather than in a horizontal position, thus ensuring the obtaining of good quality data, all with great discretion.

[0060] Also, during the phases of use of the geolocation and satellite navigation system, such a permanent vertical position of the AUV can prove to be interesting, in particular to put the antennas of the AUV out of the water, for example during the phases of recalibration of the navigation system, or communication phases (radio or satellite).

[0061] In addition, permanent verticalization can also be advantageous, particularly during the recovery phases of the AUV at sea, in particular to recover the AUV by the nose in order to extract it from the water. The initiation of verticalization of the vehicle 1 aims to move the vehicle 1 from the nominal position (illustrated in Figure 1) to a position close to vertical (illustrated in Figure 2): this is done by varying the trim angle of the vehicle, so that the vehicle, balanced in the water, goes from a trim angle of approximately zero to a trim angle greater than 60°.

[0062] In the illustrated example, the surveillance operation aims to monitor the area of ​​interest 13 by means of a camera 25. The camera 25 is arranged on an arm attached to the hull 3 of the vehicle 1. Thus, the on-board camera 25 is raised above the surface of the water 15 in the direction of the area of ​​interest 13 (by means of an arm 27), and then makes it possible to obtain images of the area of ​​interest 13 whose sharpness is satisfactory for the surveillance activities.

[0063] The initiation of the vertical positioning can be done with the adjustment boxes alone, in particular by making the rear of the vehicle 1 heavier than the front of the vehicle. For this, for example, the rear adjustment box 9 is entirely filled with liquid, while the front adjustment box 7 is entirely filled with air. Thus, the position of the center of thrust is modified, so that the position of the center of thrust is moved towards the nose 21 of the vehicle, causing a modification of the attitude angle of the vehicle.

[0064] In some cases, the initiation of the vertical setting can be carried out by means of the propulsion system, having one of the configurations as presented previously

[0065] As can be seen in Figure 2, the initiation of the vertical positioning makes it possible to obtain a trim angle of the vehicle 1 which is of the order of 70°, so that the main longitudinal axis of the vehicle is not parallel to the vertical direction 23b.

[0066] The vehicle 1 further comprises one or more arms 24, 26 which are part of the verticalization device and which are mounted by a proximal end 24a, 26a on the hull 3 and articulated in rotation relative to the hull 3, and comprising a float 28, 29 at a distal free end 24b, 26b. As explained below in detail, the arm(s) are configured to take:

[0067] - a folded position when the vehicle is in the nominal position with a substantially zero trim angle, in which the arm is substantially parallel to the main longitudinal axis of the vehicle and the float is in the immediate vicinity of the hull; - a deployed position in which the arm is inclined relative to the main longitudinal axis so as to bring and / or stabilize the vehicle into a so-called vertical position with a trim angle greater than 70° relative to its nominal position (and ideally 90°). As illustrated in Figures 3A, 3B, 4A and 4B, the autonomous underwater vehicle 30 comprises a verticalization device comprising a single arm 32. The arm 32 comprises two ends, a distal end and a proximal end.The proximal end is the end of the arm 32 which is rotatably mounted on the hull 40 of the vehicle 30 and the distal end comprises a float 34, that is to say an element whose volume density is lower than that of water. The float 34 is integral with the arm 32.

[0068] As can be seen in Figures 3A and 3B, the arm is able to be arranged in a folded position in which the float 34 is here retracted inside the hull 40 of the vehicle 30. In this folded position, the arm is arranged substantially parallel to the main longitudinal axis 38 of the vehicle 30, so as not to protrude relative to the hull 40 of the vehicle 38, and therefore not to impact the movement of the vehicle 30 (by creating drag forces).

[0069] The arm 32 is rotatably mounted on the shell 40 so as to be at least rotatably movable and to form an angle relative to the longitudinal main axis 38 in the deployed position, as illustrated in FIGS. 4A and 4B.

[0070] The axis of rotation is an axis orthogonal to the main longitudinal axis 5, and oriented in the direction 23c of the reference frame 23 reproduced in Figures 4A and 4B. The rotation of the arm 32 from the folded position to the deployed position makes it possible to place the float 34 at a distance from the hull 40 of the vehicle 30.

[0071] By thus arranging the float 34 at a distance from the hull 40 of the vehicle, the buoyancy of the float acts on the position of the center of thrust of the vehicle.

[0072] Indeed, when the arm 32 is in the deployed position, the float 34 is placed at a distance from the hull 40 of the vehicle 30, so that this influences the position of the center of thrust of the vehicle 30. In particular, the float 34 makes it possible to move a volume of water away from the hull 40 of the vehicle 30, so that the position of the hydrostatic forces applied to the vehicle 30 is modified, causing the modification of the position of the center of thrust. The deployment of the arms then makes it possible to act mainly on the position of the center of thrust, by moving it towards the nose 42 of the vehicle 1.

[0073] Thus, when the arm 32 is deployed, the vehicle can continue its movement towards the vertical and the stability of the vehicle in the vertical position can be improved. The characteristics of the arms and floats are chosen so as to allow, when the arm is deployed, to move the center of thrust towards the nose 42.

[0074] The arm 32 is advantageously arranged at the level of the lower hull of the vehicle 30.

[0075] The arm of this example is referred to as a passive arm, because its positioning relative to the main longitudinal axis 38 depends on the characteristics of the float (for example its buoyancy) but also on the length of the arm. According to certain embodiments, the arm 32 and the float 34 are configured so that, in the deployed position, the arm 32 is substantially perpendicular to the main longitudinal axis 38 of the autonomous underwater vehicle 30. In certain embodiments, the arm 32, in the deployed position, forms an angle with the main longitudinal axis 38 of the vehicle 1 comprised in the range [80; 100]

[0076] The deployment of the arm can be triggered by means of an actuator or by the initiation of the verticalization movement, as illustrated in Figures 4A and 3A (arrow 41).

[0077] In one embodiment, the arm can be deployed by means of an actuating member allowing the arm to move from a folded position to a deployed position only. Thus, the arm, once deployed, cannot be folded into the folded position, in which the float is retracted into the hull. Such a solution is particularly suitable in the context of so-called expendable autonomous underwater vehicles, which can be used only once at sea.

[0078] In particular, the actuating member comprises a spring arranged between the arm 32 and the shell 40 of the vehicle 30 and a switch (of the valve type for example, all or nothing) configured to activate the spring, so that the latter exerts a force on the arm 32 to make it pass from a folded position, substantially perpendicular to the main axis 38, to a deployed position. By activate, it is meant that the switch is configured to allow the spring to apply a force on the arm 32, so that it takes a deployed position.

[0079] Although only one arm is illustrated, it is possible to have two or more arms attached to the hull, preferably to the lower hull, on both the port and starboard sides. The arms are then preferably arranged to form an angle in the range [60°;180°[.

[0080] The operation of these so-called passive arms 32 requires the initiation of a vertical adjustment (as described above), and this by means of the adjustment boxes (not visible) and / or by the propulsion system 36 of the vehicle.

[0081] For verticalization with this passive arm 32, the adjustment boxes and / or the propulsion system 36 are controlled to initiate verticalization, and the passive arm 32 is then deployed to have a synergistic action with the adjustment boxes and / or the propulsion 36. When the deployment of the arm 32 is done by means of an actuating member, the arm 32 is then deployed “at the right time” when the initiation of verticalization allows the vehicle to have a trim angle of the order of 70°, making it possible to improve the verticality and the holding of the AUV in a vertical position.

[0082] In the case where the vehicle comprises more than one arm 32, the deployment of the arms can be done simultaneously or one after the other in a sequence, such as for example starboard then port. Referring now to Figures 5A, 5B, 6A and 6B, the vehicle 50 comprises two arms 52, 62 respectively comprising two floats 54, 64 at their distal end. The arms are preferably attached to the lower hull, respectively to port and starboard. Advantageously, the arms are arranged so as to form an angle θ in the range [60°; 180°]. The arms 52, 62 are actuable by means of an actuating member allowing one of the arms to move from a folded position to a deployed position and vice versa. In one embodiment, the actuating member making it possible to deploy the arms 52, 62 and vice versa, notably comprises a motor, capable of orienting the arms 52, 62 in several angular positions relative to the main longitudinal axis.Thus, the motorized arms 52, 62 are orientable at least around their axes of rotation (as indicated previously, orthogonal to the main longitudinal axis 58 of the vehicle 50) so as to allow the deployment of the arms 52, 62 in selected deployed positions, for example according to the angle between the main longitudinal axis 58 of the vehicle 50 and the arm 52, 62.

[0083] In one embodiment, the actuating member, i.e. the motor, is configured to adapt an angular position of the arm in the deployed position, relative to the longitudinal main axis according to the trim angle of the vehicle. For example, the vehicle 50 may comprise a verticality sensor, such as one or more accelerometers, so that the angular position of the arm is monitored and controlled according to the output signal of the verticality sensor.

[0084] This allows the angle between the arm and the vehicle hull to be regulated. This ensures good verticality of the AUV, even in the event of environmental disturbances, such as waves or water density.

[0085] Active control of the position of the arm relative to the hull 60 of the vehicle 50 makes it possible to dynamically stabilize the vehicle 50. The two motorized arms 52, 62 make it possible to maneuver the vehicle whatever its speed, and even at zero speed.

[0086] In one embodiment, the float is configured to have a variable volume. Thus, depending for example on environmental conditions (such as a sudden onset of an unusual swell), it is possible to increase the buoyancy capacity of the float and therefore stabilize the vehicle.

[0087] In one embodiment, the arm is telescopic, so that the length of the arms can be adjustable. Thus, the effect of the arms on the center of thrust can be changed by varying the length of the arms.

[0088] Of course, in an advantageous embodiment, it is possible to vary the volume of the float and the length of the arm. Although in the illustrated example, the vehicle 50 comprises two active arms 52, 62, it may in one embodiment comprise a single active arm, or more than two active arms.

[0089] In one embodiment, the verticalization device comprises, in addition to the active arms, other elements, such as the control boxes and / or the propulsion system 56. In this case, the arms 52, 62 are deployed after the verticalization is initiated by the control boxes and / or the propulsion system 56.

[0090] In one embodiment, the verticalization device is then configured to control the arms 52, 62 and / or the adjustment boxes and / or the propulsion system 56. In an advantageous embodiment, the verticalization device comprises a control unit capable of controlling different elements, in order to ensure the synchronization of their impacts on the center of thrust of the vehicle 80. The use of the motorized arms in addition to the adjustment boxes is illustrated in figures 8 to 10.

[0091] The vehicle 80 illustrated in these figures is generally cylindrical, approximately 6.5 m long and has a diameter of approximately 0.5 m. This vehicle 80 has a mass of approximately 1200 kg and when submerged, this vehicle 80 displaces approximately 1100 liters of water.

[0092] The control boxes 82, 84 of the vehicle 80 have a maximum volume of 55 liters respectively. These control boxes 82, 84 are respectively arranged 2m behind and in front of the center of gravity (CDG) and the center of thrust (CDC for center of hull in the figures) which are aligned vertically. The rear control box 82 is thus arranged between the center of gravity (or thrust) and the propulsion system 88, and the front control box 84 is arranged between the center of gravity (or thrust) and the nose 83 of the vehicle 80.

[0093] As can be seen in Figures 7 to 9, the autonomous underwater vehicle 80 comprises adjustment boxes 82, 84 which are arranged, when the vehicle 80 is in the nominal position, in an upper part 96 of the hull 86 and the arms are attached to a lower part 94 of the hull 86 of the vehicle 80.

[0094] As can be seen in the figures, in general, the adjustment boxes 82, 84 and the arms 90 are arranged on either side of the longitudinal main axis 99.

[0095] In the illustrated embodiment, the adjustment boxes are arranged inside the hull of the vehicle 80, in particular in a so-called upper part 96, which, when the vehicle 80 is sailing in the nominal position, is directed towards the surface 85. The arms are attached to the lower part 94 of the hull 86, which when the vehicle 80 is sailing in the nominal position, is directed towards the seabed 87.

[0096] The adjustment boxes allow the trim angle of the vehicle 80 to be varied. In this embodiment, only the adjustment boxes allow the trim angle of the vehicle to be varied. Figures 7, 8 and 9 illustrate three configurations of the adjustment boxes 82, 84, in which the vehicle 80 has a zero trim angle, a positive trim angle and a negative trim angle respectively, when immersed in seawater (with an estimated mass volume of 1030 kg / m 3 ).

[0097] In the first case where the trim angle is zero, i.e. when the vehicle 80 is in nominal position, the adjustment boxes are filled 60% with air at the front and 20% with air at the rear.

[0098] In the second case, where the trim angle is substantially positive, the longitudinal inclination of the vehicle 80 relative to the horizontal plane 98 drives the nose 83 of the vehicle towards the surface of the water 85. In this case, the filling of the adjustment boxes is modified so that the rear adjustment box 82 has a filling rate greater than the filling rate of the front adjustment box 84.

[0099] In the third case, where the trim angle is substantially negative, the longitudinal inclination of the vehicle 80 relative to the horizontal plane 98 drives the nose 83 of the vehicle towards the bottom 87. In this case, the filling of the adjustment boxes is modified so that the front adjustment box 84 has a filling rate greater than the filling rate of the rear adjustment box 82.

[0100] Two arms 92 are rotatably mounted on the hull 86 of the vehicle 80. At the free end of the arm 92, a float 90 is mounted. In this example, the float has a volume of approximately 10 liters.

[0101] (i.e. 20 liters for both arms). In addition, the 92 arms configured to be deployed have a length of approximately 2m.

[0102] The axis of rotation of the arms is here orthogonal to the main longitudinal axis 99. For vertical adjustment, the adjustment boxes 82, 84 are used in conjunction with the arms 92.

[0103] To place the vehicle 80 upright as described above, and to ensure zero buoyancy of the vehicle 80 in a vertical position in seawater, the adjustment boxes are filled with air to 80% at the front and 0% at the rear 82. In other words, the rear adjustment box 82 must be completely filled with liquid.

[0104] Thus adjusted, the adjustment boxes allow a vehicle attitude angle of maximum 75° to be generated. The action of the arms, by their deployment, allows regulation of the verticality of the vehicle 80, in a range of + / - 12° attitude angle around the vertical (i.e. around a attitude angle of 90°).

[0105] As can be seen in Figure 10, the arms 92a, 92b can be positioned in several isolated positions (some of which are shown in dotted lines in Figure 10). Thus, depending on the environmental conditions in which the vehicle is moving and depending on the characteristics of the vehicle 80, the position of the arms is controlled to take one or more isolated positions, when the vehicle initiates a vertical positioning or when the vehicle is in a vertical position, so as to form an angle greater than 0° and less than 180° with the main longitudinal axis of the vehicle 80. The deployment of one or more arms in one of the deployed positions as illustrated in Figure 10 is carried out according to a method comprising in particular a step in which, when the attitude angle of the vehicle reaches a first threshold angle, the arm(s) is / are actuated to put it in the deployed position, from the folded position.

[0106] For example, the deployment of the arms of the vehicle 80 can be carried out following a modification of the trim angle of the vehicle, for example by the use of the adjustment boxes 82, 84 and / or the propulsion system, so that this trim angle becomes greater than or equal to the first threshold angle.

[0107] In one embodiment, the verticalization of the vehicle 80 is initiated prior to the deployment of the arms, and carried out for example by means of the adjustment boxes 82, 84 and / or the propulsion system. For example, the initialization of the verticalization by means of the adjustment boxes allows the vehicle 80 to reach a trim angle of approximately 75°.

[0108] In one embodiment, the first threshold angle of 70° may be specified, such that the arms are deployed when the vehicle trim angle 80 exceeds 70° via the adjustment boxes.

[0109] The method may also comprise a step of folding the arm(s) of the vehicle 80, when the attitude angle of the vehicle 80 becomes less than a second threshold angle.

[0110] Thus, when the vehicle is maneuvered to resume a nominal position for subsequent navigation, the arms are configured to be actuated and folded, when the trim angle becomes lower than the second threshold value.

Claims

CLAIMS 1. Autonomous underwater vehicle (1, 30, 50, 80) comprising a hull (3, 40, 60, 86) extending along a longitudinal main axis (5, 38, 58, 99), at least one device for verticalizing the vehicle configured to modify a trim angle of the vehicle (1, 30, 50, 80) between a nominal horizontal position of the vehicle and a vertical position of the vehicle, characterized in that the device for verticalizing the vehicle comprises one or more arms (24, 26, 32, 52, 62, 92) mounted by a proximal end (24a, 26a) on the hull (3, 40, 60, 86) and articulated in rotation relative to the hull (3, 40, 60, 86), and comprising a float (28, 29, 34, 54, 64, 90) at a distal free end (24b, 26b) such that the arm (24, 26, 32, 52, 62, 92) is configured to take: - a folded position when the vehicle is in the nominal position with a substantially zero trim angle, in which the arm (24, 26, 32, 52, 62, 92) is substantially parallel to the main longitudinal axis (5, 38, 58, 99) of the vehicle (1, 30, 50, 80) and the float (28, 29, 34, 54, 64, 90) is in the immediate vicinity of the hull (3, 40, 60, 86); - a deployed position in which the arm (24, 26, 32, 52, 62, 92) is inclined relative to the main longitudinal axis (5, 38, 58, 99) so as to bring and / or stabilize the vehicle (1, 30, 50, 80) into a so-called vertical position with a trim angle greater than 70° relative to its nominal position.

2. Autonomous underwater vehicle (1, 50, 80) according to claim 1, comprising at least two arms (24, 26, 52, 62, 92), fixed to the hull on the port and starboard sides, arranged so as to form an angle (66) included in the range [60°; 180°[.

3. Autonomous underwater vehicle (1, 30, 50, 80) according to one of claims 1 and 2, comprising at least one actuating member allowing the arm (24, 26, 32, 52, 62, 92) to move from the folded position to the deployed position.

4. An autonomous underwater vehicle (50, 80) according to claim 3, wherein the actuating member further allows the arm (52, 62, 92) to move from the deployed position to the folded position.

5. Autonomous underwater vehicle (50, 80) according to claim 4, wherein the actuating member is capable of orienting the arm (52, 62, 92) in a determined or selected angular position relative to the main longitudinal axis (58, 99).

6. Autonomous underwater vehicle (50, 80) according to claim 5, wherein the actuating member is configured to adapt, according to the trim angle of the vehicle, the angular position of the arm (52, 62, 92) in the deployed position, relative to the main longitudinal axis (58, 99).

7. An autonomous underwater vehicle (50, 80) according to one of claims 4 and 5, further comprising a verticality sensor, such as an accelerometer, so that the angular position of the arm (52, 62, 92) is controlled as a function of the output signal of the verticality sensor.

8. An autonomous underwater vehicle (1, 30, 50, 80) according to any one of claims 1 to 7, wherein the float (28, 29, 34, 54, 64, 90) has a variable volume.

9. An autonomous underwater vehicle (1, 30, 50, 80) according to any one of claims 1 to 8, wherein at least one of the arms (24, 26, 32, 52, 62, 92) is telescopic.

10. Autonomous underwater vehicle (1, 80) according to any one of claims 1 to 9 comprising one or more adjustment boxes (7, 9, 82, 84) and / or one or more propellers, capable of varying the trim angle of the vehicle (1, 80).

11. Autonomous underwater vehicle (1, 80) according to claim 10, wherein the adjustment boxes (7, 9, 82, 84) are arranged, when the vehicle (1, 80) is in nominal position, in an upper part of the hull (3, 86) and the arms (24, 26, 92) are attached to a lower part of the hull (3, 86) of the vehicle (1, 80).

12. Method for placing an autonomous underwater vehicle (1, 30, 50, 80) vertically according to any one of the preceding claims, comprising actuating the arm (24, 26, 32, 52, 62, 92) to place it in the deployed position, from the folded position, in particular when the trim angle of the vehicle (1, 30, 50, 80) reaches a first threshold angle.

13. Method for verticalization according to claims 10 and 12, comprising first initiating the verticalization of the vehicle (1, 80) by means of the adjustment boxes (7, 9, 82, 84) or the propellers of the vehicle (1, 80).

14. Method for verticalization according to one of claims 12 and 13 comprising actuating the arm (52, 62, 92) to place it in the folded position from the deployed position when the trim angle of the vehicle (50, 80) is less than a second threshold angle.