Underwater glider with improved autonomy

Abstract

Underwater glider with improved autonomy The underwater glider comprises a hull (4), a ballasting system (6), an attitude adjustment system (8) configured to modify a distribution of the masses of the underwater glider so as to modify the attitude of the underwater glider, and a power system (10) comprising an electric battery (12) connected to the ballasting system (6) and to the attitude control system (8) for their supply of electric energy and a recharging system (14) for charging the electric battery (12), the recharging system (14) comprising a photovoltaic panel (16). Figure for abstract: Figure 1

Description

Title of the invention: Underwater glider with improved autonomy

[0001] The present invention relates to the field of underwater gliders, in particular underwater gliders intended to carry out long-term measurement campaigns at sea.

[0002] An underwater glider is provided with a ballasting system for controlling the descent and ascent of the underwater glider, the underwater glider being configured such that a descent or ascent movement of the underwater glider generates a forward propulsive force of the underwater glider.

[0003] The generation of the propulsion force results from the shape of the hull of the underwater glider and / or hydrodynamic appendages arranged on the hull of the underwater glider. The hydrodynamic appendages comprise, for example, wings and / or ailerons.

[0004] In operation, the ballasting system is controlled to cause alternating descents and ascents of the underwater glider to allow the underwater glider to move forward.

[0005] A ballast system uses little energy. An underwater glider can therefore carry out long-duration missions by covering long distances autonomously.

[0006] One of the aims of the invention is to propose an underwater glider with improved autonomy.

[0007] For this purpose, the invention proposes an underwater glider comprising a hull, a ballasting system, an attitude adjustment system configured to modify a distribution of the masses of the underwater glider so as to modify the attitude of the underwater glider, and a power supply system comprising an electric battery connected to the ballasting system and to the attitude control system for their supply of electric energy and a recharging system for charging the electric battery, the recharging system comprising a photovoltaic panel.

[0008] The recharging system comprising a photovoltaic panel makes it possible to convert solar energy into electrical energy stored in the electric battery when the underwater glider is on the surface.

[0009] The possibility of recharging the electric battery using solar energy makes it possible to increase the autonomy of the underwater glider and / or to use an electric battery of lower capacity, which also makes it possible to increase the autonomy of the underwater glider by making it lighter.

[0010] The attitude control system of the underwater glider can control the trajectory of the underwater glider efficiently with low expenditure. energy, especially compared to movable rudders which can increase the hydrodynamic drag of the underwater glider.

[0011] The combination of the recharging system and the mass displacement attitude control system therefore makes it possible to obtain an underwater glider with very long operating autonomy.

[0012] According to other advantageous aspects of the invention, the underwater glider comprises one or more of the following optional features, taken individually or in all technically possible combinations:

[0013] - the photovoltaic panel is flat in shape and extends along a plane, the panel photovoltaic being fixed on the hull in such a way that said plane is parallel to the direction of movement of the underwater glider;

[0014] - the photovoltaic panel is fixed on the back of the hull;

[0015] - the photovoltaic panel extends substantially horizontally when the attitude of the underwater glider is horizontal;

[0016] - the underwater glider is configured to hold the photovoltaic panel at the water surface or underwater at a depth of between 1 cm and 10 cm during a battery recharging phase using the photovoltaic panel;

[0017] - the recharging system is of the maximum power point tracking type.

[0018] - the photovoltaic panel has an elongated rectangular shape along the axis longitudinal of the hull.

[0019] - the photovoltaic panel is flexible;

[0020] - the photovoltaic panel and its fixing members on the hull have a density not exceeding 40% that of sea water;

[0021] - the battery has a capacity equal to or less than 6,000 Wh;

[0022] - the underwater glider is configured for a standby of the system of reloading when the underwater glider is submerged;

[0023] - the underwater glider comprises hydrodynamic appendages arranged on the hull, all hydrodynamic appendages being fixed;

[0024] - the attitude control system is configured to move the electric battery so as to modify the distribution of masses;

[0025] - the attitude control system is configured to modify a roll angle and / or a pitch angle of the underwater glider;

[0026] - the underwater glider comprises a measuring system comprising one or more sensors and an acquisition device, the measuring system being connected to the electric battery for its electrical energy supply;

[0027] - the underwater glider comprises a telecommunication system, the system of telecommunication being connected to the electric battery for its supply of electric energy;

[0028] - the underwater glider comprises a solar radiation measuring system, comprising for example at least one brightness sensor;

[0029] - the underwater glider is programmed to remain on the surface for a duration of recharge received in the form of instructions via a telecommunications system of the underwater glider or calculated by the underwater glider based on a measurement of solar radiation carried out using an on-board solar radiation measuring system.

[0030] The invention and its advantages will be better understood on reading the description which follows, given solely as a non-limiting example, and made with reference to the drawings in which:

[0031] [Fig-1] [Fig.l] is a schematic view of the underwater glider illustrating on-board systems of the underwater glider.

[0032] [Fig.2] [Fig.2] is a side view of the underwater glider of [Fig.l];

[0033] [Fig.3] [Fig.3] is a top view of the underwater glider of [Fig.l];

[0034] [Fig.4] [Fig.4] is a front view of the underwater glider of [Fig.l];

[0035] [Fig.5] [Fig.5] is a side view of the underwater glider in descent

[0036] [Fig.6] [Fig.6] is a side view of the underwater glider in climb

[0037] [Fig.7] [Fig.7] is a graph illustrating a descent and ascent cycle of the underwater glider.

[0038] As illustrated in [Fig.l], an underwater glider 2 comprises a hull 4, a ballast system 6 configured to modify the buoyancy of the underwater glider 2, an attitude control system 8 configured to control the attitude of the underwater glider 2 by modifying the mass distribution of the underwater glider 2, and an electrical power system 10, the electrical power system 10 comprising an electric battery 12 electrically connected to the ballast system 6 and to the attitude control system 8 for their power supply and a recharging system 14 for charging the electric battery 12, the recharging system 14 comprising a photovoltaic panel 16.

[0039] The attitude of the underwater glider 2 designates its orientation in three-dimensional space.

[0040] Subsequently, the terms of orientation of the underwater glider 2 are used with reference to the usual orthogonal reference frame of marine vehicles comprising a roll axis X oriented from rear to front, a pitch axis Y oriented from right to left and a yaw axis Z oriented from bottom to top.

[0041] As illustrated in Figures 1 to 3, the hull 4 is profiled along the roll axis X. The hull 4 has, for example, an elongated shape along the roll axis X.

[0042] The hull 4 has for example a shape of revolution around the roll axis X. The hull 4 has for example a diameter which gradually increases then gradually decreasing from a front end 4A of the hull 4 towards a rear end 4B of the hull 4.

[0043] Other shapes are possible for the hull 4.

[0044] In one example, the hull 4 has a wing shape or an elongated shape along the roll axis X with a non-circular cross-section, for example a polygonal cross-section, preferably with rounded apexes.

[0045] The hull 4 is optionally provided with fixed hydrodynamic appendages 18 arranged on the hull 4. By “fixed”, we mean that the hydrodynamic appendages 18 are immobile relative to the hull 4. The hull 4 is for example provided with fins arranged near the rear end 4B of the hull 4.

[0046] The underwater glider 2 is preferably devoid of movable hydrodynamic appendages. In particular, the underwater glider 2 is devoid of a movable wing, a movable fin, a movable rudder or a movable flap.

[0047] As illustrated in [Fig.l], the ballasting system 6 is configured to modify the buoyancy of the underwater glider 2 so as to cause a descent of the underwater glider 2 or a rise of the underwater glider 2.

[0048] The ballast system 6 comprises for example an internal tank 20 and an elastically deformable external bladder 22, the internal tank 20 and the external bladder 22 containing a ballast liquid and being fluidically connected by means of a pump 24 configured to transfer the ballast liquid between the internal tank 20 and the external bladder 22. The ballast liquid is for example an oil.

[0049] The volume occupied by the external bladder 22 varies depending on the quantity of ballast liquid contained in the external bladder 22 which is submerged.

[0050] The external bladder 22 is arranged to be submerged when the underwater glider 2 is in the water.

[0051] The buoyancy of the underwater glider 2 varies according to the volume of the external bladder 22 and therefore according to the quantity of ballast liquid contained in the external bladder 22.

[0052] The hull 4 delimits a watertight compartment 26 configured so that water does not penetrate into this watertight compartment 26.

[0053] Preferably, the internal reservoir 20 and / or the pump 24 are arranged in the sealed compartment 26.

[0054] Advantageously, the shell 4 delimits a wet compartment 28 configured so that water penetrates into this wet compartment 28.

[0055] Preferably, the external bladder 22 is disposed in the wet compartment 28.

[0056] This allows the external bladder 22 to be arranged inside the hydrodynamically profiled hull 4, which limits the hydrodynamic drag of the sub-glider. sailor 2, while varying the buoyancy of the underwater glider according to the volume of the external bladder 22.

[0057] The attitude control system 8 is configured to modify the attitude of underwater glider 2 by modifying the mass distribution of underwater glider 2.

[0058] The attitude control system 8 is in particular configured to modify the front-rear mass distribution of the underwater glider 2 to modify the pitch angle of the underwater glider 2.

[0059] The modification of the pitch angle of the underwater glider 2 combined with the vertical movement generated by the ballasting system 6 makes it possible to control the advance of the underwater glider 2.

[0060] The attitude control system 8 is advantageously configured to modify the left-right mass distribution of the underwater glider 2 to modify the roll angle of the underwater glider 2.

[0061] Changing the roll angle of the underwater glider 2 allows the underwater glider 2 to turn to the left or to the right during a climb or descent of the underwater glider 2.

[0062] The battery 12 is received inside the hull 4, in particular inside the watertight compartment 26.

[0063] The attitude control system 8 is for example configured to modify the distribution of the masses of the underwater glider 2 by moving one or more internal masses. Each internal mass is located inside the hull 4, in particular in the watertight compartment 26.

[0064] The attitude control system 8 is advantageously configured to modify the distribution of the masses of the underwater glider 2 by moving the battery 12 relative to the hull 4.

[0065] As illustrated by the arrows M, the battery 12 is, for example, mounted inside the hull 4, in particular inside the sealed compartment 26 of the hull 4, being movable relative to the hull 4, along the roll axis and / or along the pitch axis.

[0066] The attitude control system 8 comprises an actuator 30 configured to move the battery 12 relative to the hull 4 along the roll axis and / or along the pitch axis.

[0067] The movement of the battery 12 along the roll axis makes it possible to modify the front - rear mass distribution. The movement of the battery 12 along the pitch axis makes it possible to modify the left - right mass distribution.

[0068] As can be seen in Figures 1 to 4, the photovoltaic panel 16 has an upper surface 16A on which one or more photovoltaic cells 32 are arranged.

[0069] Each photovoltaic cell 32 is configured to convert solar energy into electrical energy.

[0070] The photovoltaic panel 16 is fixed to the shell 4, outside the shell 4, for example using one or more fixing members 34, such as flanges ([Fig.4]).

[0071] Preferably, the photovoltaic panel 16 and its fixing members 34 on the hull have a density not exceeding 40% that of sea water. This makes it possible to limit the modification of the buoyancy of the underwater glider 2 on which the photovoltaic panel 16 is fixed.

[0072] The photovoltaic panel 16 is preferably configured and fixed on the hull 4 in such a way that the photovoltaic panel 16 has minimal drag during a downward and forward movement of the underwater glider 2 and an upward and forward movement of the underwater glider 2, and possibly generates additional lift provided by the angle of attack of the flow on the photovoltaic panel 16.

[0073] Preferably, the photovoltaic panel 16 is of substantially planar shape and fixed to the hull 4 in such a way that the photovoltaic panel 16 is parallel to the direction of movement of the underwater glider 2.

[0074] The photovoltaic panel 16 is advantageously fixed on the back of the hull 4, i.e. the part of the hull 4 facing upwards when the underwater glider 2 has a horizontal attitude, i.e. a zero pitch angle and a zero roll angle.

[0075] Preferably, the photovoltaic panel 16 is fixed to the hull 4 so that the upper surface 16A of the photovoltaic panel 16 extends along a substantially horizontal plane when the underwater glider 2 has a horizontal attitude.

[0076] The shell 4 has a length Lc taken along the transverse axis Y. The photovoltaic panel 16 has a length LP taken along the transverse axis Y.

[0077] Preferably, the ratio of the length LP of the photovoltaic panel 16 to the length Lc of the shell 4 is less than 1.

[0078] The shell 4 has a maximum width LCMax taken along the transverse axis Y. The photovoltaic panel 16 has a maximum width LP MAX taken along the transverse axis Y.

[0079] The ratio of the maximum width LP MAx of the photovoltaic panel 16 to the maximum width LCMax of the hull 4 results from a hydrodynamic compromise. A high ratio increases the lift generated by the photovoltaic panel 16, but also the drag of the underwater glider 2.

[0080] In a first example where the screen is favored, this ratio is less than 2 and / or greater than 1. In a mode where the lift is favored, this ratio is greater than 1 and less than 6.

[0081] Limiting the length and / or width of the photovoltaic panel 16 relative to those of the hull 4 makes it possible to limit an increase in the hydrodynamic drag of the underwater glider 2 caused by the presence of the photovoltaic panel 16 on the back of the hull 4.

[0082] The provision of minimum values ​​makes it possible to have a photovoltaic panel 16 having a sufficient surface area to ensure the electrical recharging of the underwater glider 2.

[0083] The photovoltaic panel 16 has, for example, a flat plate shape. The upper surface 16A of the photovoltaic panel is the upper face of the photovoltaic panel 16 in the shape of a flat plate.

[0084] The photovoltaic panel 16 has, for example, a rectangular outline. The long sides of the photovoltaic panel 16 are preferably parallel to the roll axis X, the short sides being parallel to the pitch axis Y.

[0085] Other shapes are conceivable. The photovoltaic panel 16 alternatively has an elliptical or circular outline.

[0086] The photovoltaic panel 16 is preferably flexible in such a way as to allow elastic deformation of the photovoltaic panel 16.

[0087] This prevents the photovoltaic panel from breaking when it is subjected to an impact, for example during handling of the underwater glider to launch it or to recover it, in particular from a ship.

[0088] The battery 12 is electrically connected to the photovoltaic panel 16 for recharging the battery 12 with electrical energy with the electrical energy produced by the photovoltaic panel 16.

[0089] The recharging system 14 preferably comprises an electrical recharging unit 36, the battery 12 being electrically connected to the photovoltaic panel 16 via the electrical recharging unit 36.

[0090] The electrical recharging unit 36 ​​is configured to control the charging of the battery 12 using the photovoltaic panel 16.

[0091] The underwater glider 2 comprises for example a measuring system 38 for carrying out measurements relating to the water (temperature, pressure, etc.).

[0092] The underwater glider 2 advantageously comprises a solar radiation measurement system 40, comprising for example at least one brightness sensor 42 arranged so as to measure the brightness, in particular when the underwater glider 2 is close to the surface of the water with a horizontal attitude for recharging the battery 12 using the photovoltaic panel 16.

[0093] The recharging system 14 comprises for example an active mode in which the battery 12 is charged using the photovoltaic panel 16 and an inactive mode in which the recharging system 14 is deactivated. The inactive mode makes it possible to save electrical energy consumed by the recharging system 14 when the underwater vehicle 2 is underwater.

[0094] The recharging system 14 is preferably of the maximum power point tracking (MPPT) type. Such a recharging system 14 makes it possible to optimize the recharging of the battery 12 from the photovoltaic panel 16, although the latter delivers a non-linear output power, taking into account, for example, the variability of the operating conditions, such as sunshine or temperature.

[0095] The underwater glider 2 comprises for example a telecommunications system 44 configured to transmit and / or receive communications signals, preferably by radio waves.

[0096] The telecommunications system 44 is for example configured to receive instructions intended to be implemented by the underwater glider 2. The instructions comprise for example a navigation plan (i.e. a trajectory to follow) and / or measurements to be carried out using a measurement system 38 on board the underwater vehicle 2 and / or instructions relating to the recharging of the battery 12 and / or data relating to the conditions in which the recharging of the battery 12 is carried out.

[0097] The telecommunications system 44 is for example configured to transmit measurement reports generated by the measurement system 38.

[0098] The telecommunications system 44 comprises an antenna 46 for transmitting and / or receiving communication signals.

[0099] The underwater glider 2 advantageously comprises an electronic control unit 48 configured to control the on-board systems of the underwater glider 2, for example to implement the different configurations and the different operating modes indicated below.

[0100] The electronic control unit 48 is connected to the on-board systems of the underwater glider 2 (solid arrows) to control them.

[0101] The electronic control unit 48 is configured to control the underwater vehicle 2 during a recharging phase, in particular to adjust the recharging duration during which the underwater glider 2 remains close to the surface and with a neutral (or zero) attitude in order to recharge the battery 12 using the photovoltaic panel 16.

[0102] The recharge duration is for example an instruction received by the electronic control unit 48, for example via the telecommunications system 44 or calculated by the electronic control unit 48.

[0103] In this case, the electronic control unit 48 is advantageously configured to calculate a recharging time, for example as a function of the sunshine, and in particular as a function of the time of day (in particular day / night) and / or a measurement of the solar radiation provided by the brightness sensor 42.

[0104] The battery 12 is electrically connected to the on-board systems of the underwater glider 2 for their supply of electrical energy 12 (dotted arrows). In particular, the electric battery 12 is electrically connected to the ballast system 6 and to the attitude control system 8 for their supply of electrical energy.

[0105] Preferably, the electronic control unit 48 is configured to control the ballast system 6, in particular the pump 24, to control the attitude control system 8, in particular the actuator 30, and / or to control the recharging system 14, in particular the electrical recharging unit 36.

[0106] Where appropriate, the electronic control unit 48 is for example configured to activate and deactivate the measurement system 38, and / or to control the telecommunication system 44, for example for receiving instructions and / or sending measurement reports provided by the measurement system 38 via the telecommunication system 44.

[0107] As illustrated in particular in Figures 5 and 6, the underwater glider 2 is configured in such a way that a downward movement of the underwater glider 2 generates a propulsion force of the underwater glider 2 forward ([Fig.5]) and that an upward movement of the underwater glider 2 generates a propulsion force of the underwater glider 2 forward ([Fig.6]).

[0108] The propulsion force is generated for example due to the shape of the hull 4 of the underwater glider 2 and / or by any fixed hydrodynamic appendages 18 arranged on the hull 4, such as fins.

[0109] The propulsion force (Arrow F) is generated during a descent movement (Arrow D) when the underwater glider 2 has an attitude such that the front end of the hull 4 is raised relative to the rear end of the hull 4 ([Fig.5]).

[0110] The underwater glider 2 has a descent configuration in which the ballast system 6 is controlled to decrease the buoyancy of the underwater glider 2 so as to cause it to descend, and the attitude control system 8 is controlled to modify the mass distribution by increasing the mass at the front and reducing the mass at the rear, such that the front end of the hull 4 is raised relative to the rear end of the hull 4.

[0111] The attitude control system 8 is in particular controlled to move the battery 12 forward relative to a neutral position in which the underwater glider 2 has a neutral attitude.

[0112] The propulsion force (Arrow F) is for example generated during a rising movement (Arrow U) when the underwater glider 2 has an attitude such that the front end 4A of the hull 4 is raised relative to the rear end 4B of the hull 4 ([Fig.6]).

[0113] The underwater glider 2 has a climb configuration in which the ballast system 6 is controlled to increase the buoyancy of the underwater glider 2 so as to cause it to climb, and the attitude control system 8 is controlled to modify the mass distribution by decreasing the mass at the front and increasing the mass at the rear, such that the front end of the hull 4 is lowered relative to the rear end of the hull 4.

[0114] The underwater glider 2 is configured to recharge the battery 12 when the underwater glider 2 is on the surface, and preferably with a neutral attitude.

[0115] This makes it possible to place the photovoltaic panel 16 close to the surface of the water with the upper surface 16A substantially horizontal for good efficiency.

[0116] During recharging, the upper surface 16A of the photovoltaic panel 16 is for example located above the surface of the water, on the surface of the water or below the surface of the water.

[0117] Preferably, the underwater glider 2 is configured to position itself during the recharging of the battery 12 using the photovoltaic panel 16 with a neutral attitude, the upper surface 16A being located under the surface of the water, for example at a depth of a few centimeters (for example a depth of between 1 cm and 10 cm)

[0118] This allows both passive cooling and a change in optical refractive index between air and water to be benefited from, which advantageously causes refraction of the light rays so that the angle of refraction of the refracted rays (which pass through the air / water interface and reach the photovoltaic panel 16) is less than the angle of incidence of the incident light rays. The refracted rays reaching the photovoltaic panel 16 are therefore angularly closer to the normal to the upper surface 16A of the photovoltaic panel 16 than the incident rays. This improves the efficiency of the photovoltaic panel 16 not placed perpendicular to the rays.

[0119] The underwater glider 2 has a loading configuration in which the ballasting system 6 is controlled to keep the underwater glider 2 on the surface, the attitude control system 8 is controlled to position the underwater glider 2 with a neutral attitude, and the recharging system 14 is commanded to charge the battery 12 using the photovoltaic panel 16, in particular by activating the recharging system 14.

[0120] Preferably, the underwater glider 2 is configured to put the recharging system 14 in inactive mode when the underwater glider 2 is submerged. In particular, the underwater glider 2 is configured to put the electrical recharging unit 36 ​​in inactive mode when the underwater glider 2 is submerged.

[0121] This limits the electricity consumption of the recharging system 14 when the underwater glider 2 is submerged and recharging the battery 12 using the photovoltaic panel 16 is not possible in any case.

[0122] Preferably, the underwater glider 2 is configured to put the telecommunications system 44 in inactive mode when the underwater glider 2 is submerged.

[0123] This limits the electricity consumption of the telecommunications system 44 when the underwater glider 2 is submerged and the transmission of signals is difficult or even impossible.

[0124] Preferably, the underwater glider 2 has a communication configuration in which the ballast system 6 is controlled to keep the underwater glider 2 at or near the water surface, the attitude control system 8 is controlled to modify the mass distribution so that the front end 4A of the hull 4 is lower than the rear end 4B of the hull 4, such that the antenna 46 emerges from the water.

[0125] This allows the transmission of communication signals via the telecommunications system 44 when the underwater glider 2 is on the surface.

[0126] The attitude control system 8 is in particular controlled to move the battery 12 forward relative to the neutral position in which the underwater glider 2 has a neutral attitude.

[0127] As illustrated in [Fig.7], the underwater glider 2 is for example configured to cyclically implement a diving cycle C comprising a recharging step E1 in which the underwater glider 2 is in the recharging configuration for charging the battery 12 before a dive, followed by a diving preparation step E2 in which the underwater glider 2 switches to the diving configuration to descend and advance, followed by a diving step E3 in which the underwater glider 2 in the diving configuration advances while descending, followed by an ascent preparation step E4 in which the underwater glider switches to the ascent configuration, followed by an ascent step E5 in which the underwater glider 2 in the ascent configuration advances while climbing, followed, once the underwater glider 2 has returned to the surface, by a step E6 communication in which the underwater glider 2 is in communication configuration for transmitting communication signals.

[0128] Cycle C is presented as an example. Other cycles are possible.

[0129] It is for example possible to provide a cycle comprising a communication step E6 between the reloading step E1 and the dive preparation step E2, instead of or in addition to the communication step carried out at the end of the ascent step E5.

[0130] It is for example possible to provide a cycle comprising a communication step E6 at the start of the cycle and a reloading step E1 at the end of the cycle.

[0131] It is for example possible to provide several communication steps E6 interspersing a long reloading step E1.

[0132] It is possible to provide a cycle alternating several diving steps E3 and ascent steps E5 (with the associated diving preparation steps E2 and ascent preparation steps E4) between two successive reloading steps E1 and / or between two communication steps E6.

[0133] This is possible if the battery 12 has sufficient capacity and / or if the measuring system 38 is capable of storing sufficient measurement data. This makes it possible to limit the time spent on the surface relative to the time spent underwater, during which the underwater glider 2 can carry out measurements.

[0134] The underwater glider 2 provides very high autonomy, which makes it possible, for example, to carry out measurement campaigns over very large areas.

[0135] Piloting the underwater glider 2 using a ballast system 6 and an attitude control system 8 by modifying the distribution of the masses of the underwater glider makes it possible to pilot the underwater glider 2 in a very energy-efficient manner.

[0136] Trajectory control is achieved by moving internal mass(es) without any mobile submerged appendage.

[0137] The ballasting system 6 using a deformable external bladder 22 is energy efficient, a low power pump 24 being sufficient to fill and empty the deformable external bladder 22 from the internal tank 20.

[0138] Changing the mass distribution by moving the battery 12 makes it possible to effectively change the mass distribution with low energy consumption.

[0139] The possible fixed hydrodynamic appendages 18 do not require an actuator which contributes to the low energy consumption for the operation of the underwater glider 2.

[0140] The power supply system 10 comprising the battery 12 rechargeable using the photovoltaic panel 16 makes it possible to recharge the battery 12 between two dives of the underwater glider 2.

Claims

Claims

1. An underwater glider comprising a hull (4), a ballasting system (6), an attitude adjustment system (8) configured to modify a mass distribution of the underwater glider so as to modify the attitude of the underwater glider, and a power supply system (10) comprising an electric battery (12) connected to the ballasting system (6) and to the attitude control system (8) for their supply of electrical energy and a recharging system (14) for charging the electric battery (12), the recharging system (14) comprising a photovoltaic panel (16), wherein the photovoltaic panel (16) is planar in shape and extends along a plane, the photovoltaic panel being fixed to the hull (4) in such a way that said plane is substantially parallel to the direction of movement of the underwater glider,and in which the photovoltaic panel (16) and its fixing members on the hull (4) have a density not exceeding 40% that of sea water.,

2. An underwater glider according to claim 1, wherein the photovoltaic panel is fixed on the back of the hull (4).

3. An underwater glider according to claim 1 or 2, wherein the photovoltaic panel (16) extends substantially horizontally when the attitude of the underwater glider is horizontal.

4. Underwater glider according to any one of the preceding claims, configured to maintain the photovoltaic panel (16) on the surface of the water or underwater at a depth of between 1 cm and 10 cm during a phase of recharging the battery (12) using the photovoltaic panel (16).

5. An underwater glider according to any preceding claim, wherein the recharging system (14) is of the maximum power point tracking (MPPT) type.

6. Underwater glider according to any one of the preceding claims, having an elongated rectangular shape along a longitudinal axis (X) of the hull (4).

7. An underwater glider according to any preceding claim, wherein the photovoltaic panel (16) is flexible.

8. An underwater glider according to any preceding claim, wherein the battery (12) has a capacity equal to or less than 6,000 Wh.

9. An underwater glider according to any preceding claim, configured to put the recharging system (14) on standby when the underwater glider is submerged.

10. An underwater glider according to any preceding claim, comprising hydrodynamic appendages (18) arranged on the hull (4), all the hydrodynamic appendages (18) being fixed.

11. An underwater glider according to any preceding claim, wherein the attitude control system (8) is configured to move the battery (12) so as to alter the mass distribution.

12. An underwater glider according to any preceding claim, wherein the attitude control system (8) is configured to modify a roll angle and / or a pitch angle of the underwater glider.

13. An underwater glider according to any preceding claim, comprising a measuring system (38) comprising one or more sensors, the measuring system being connected to the battery (12) for its electrical power supply.

14. An underwater glider according to any preceding claim, comprising a telecommunication system, the telecommunication system being connected to the electric battery for its supply of electrical energy.

15. Underwater glider according to any one of the preceding claims, comprising a solar radiation measuring system (40), comprising for example at least one brightness sensor (42).

16. An underwater glider according to any preceding claim, programmed to remain on the surface for a recharge duration received in the form of instructions via a telecommunications system (44) of the underwater glider or calculated by the underwater glider based on a measurement of solar radiation carried out using an onboard solar radiation measurement system (40).

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