Autonomous mobile platform capable of operating in a fluid environment such as water and on land.

Abstract

Autonomous mobile platform capable of operating in a fluid medium such as water and on land. Mobile platform P, for carrying out underwater and / or land reconnaissance, comprising: a central body C, with a central axis 100; and, four thrusters P1, P3 arranged around the central body; each thruster comprising: an actuator A1, A3, provided with a fin PA1, PA3; and, an actuation module MA1, MA3, designed to generate a rotation of the actuator around its main axis X1, X3 and a deformation of the corresponding fin. Abstract figure: figure 1

Description

Title of the invention: Autonomous mobile platform capable of moving in a fluid medium such as water and on land.

[0001] The present invention relates to the field of autonomous platforms capable of evolving in a fluid medium such as water, in particular for carrying out underwater missions, in particular for carrying out underwater observations of fauna and flora, and acoustically discreet missions; it also relates to the field of autonomous platforms capable of evolving on land.

[0002] A platform used for observing natural environments, particularly in aquatic environments, must disturb this environment as little as possible. It must also meet the requirements imposed by navigation in an underwater environment. Such a platform must also be able to move within the environment without being significantly disturbed, particularly by flora, in particular by the presence of algae. Existing platforms are still too disruptive to observe fauna in conditions of sufficient discretion.

[0003] It is also known that one of the major difficulties which arises when designing devices of this type lies in resolving stability problems, in particular in the stationary state, for example when acquiring and maintaining an orientation in order to carry out a precise observation.

[0004] In this respect, French patent FR 2 796 217 proposes a remote-controlled mobile platform capable of moving in an environment such as water or air; this platform has a density close to that of the environment in which it is located and comprises at least two pairs of thrusters that can be steered in two planes parallel to each other and to the longitudinal axis of the platform. In the underwater version, the platform is equipped with four hydraulic reactors, each of which can be steered around an axis perpendicular to the longitudinal axis of the platform; so-called "vector" control of the platform allows it to move in the underwater environment in a manner identical to that of a rotary wing in an aerial environment.

[0005] This configuration requires real-time management of 3 degrees of freedom per thruster (variable speed in forward gear, variable speed in reverse gear and thruster orientation), i.e. twelve degrees of freedom in total, so as to maintain its horizontal attitude. However, propeller thrusters do not meet the requirements of discretion with regard to wildlife and, moreover, can be disturbed by the presence of algae.

[0006] French patent FR 2 942 451 proposes an underwater propulsion process of a platform comprising a rigid structure of elongated shape, an elongated deformable element, carried by the rigid structure, which consists of generating a deformation of the deformable element using several actuators, in the form of a progressive wave in the opposite direction to the propulsion during the acceleration phase or in the direct direction during the deceleration phase, and in a deformation in the form of a sustained wave during the cruising phase, the deformation is directed essentially along the main axis of movement, the elongations of the progressive and sustained waves being oriented perpendicular to the main axis of the rigid structure. This propulsion method makes it possible to move the platform in a preferred direction, in a particularly discreet manner, without being disturbed by the presence of algae, but does not meet the requirements imposed by maintaining it in a stationary state in order to carry out precise observation.

[0007] The aim of the invention is to propose a platform which combines discretion and maneuverability, in order to allow precise and faithful observation of a natural environment, in particular an aquatic environment, and, preferably, also to allow precise and faithful observation on land.

[0008] To achieve this aim, the invention proposes an energetically autonomous mobile platform capable of evolving in an environment such as water and / or on land, in particular to carry out underwater and / or land reconnaissance, characterized in that it comprises:

[0009] - a central body, with a central axis; And,

[0010] - at least three, preferably four, thrusters arranged around the central body;

[0011] each propellant comprising:

[0012] - an actuator, provided, at a distal end, with a flipper; and,

[0013] - an actuation module secured to the central body and having a main axis preferably oblique to said central axis and designed to cause rotation of the actuator around the main axis and deformation of the fin.

[0014] The actuator advantageously comprises articulated arms in the form of a pantograph, a central actuating arm of which extends along the main axis, the actuating module being designed to generate a rotation of the central arm around the main axis and a translation of this central shaft along the same main axis, so that the distal end forms a more or less large angle with the main axis.

[0015] Each articulated arm may comprise:

[0016] - a first main arm, orientable at a first of its ends, in the vicinity of the central body, around an axis;

[0017] - a second main arm orientable at a first of its ends, in the vicinity of a second end of the first main arm, around an axis parallel to an axis of the first main arm;

[0018] - a first secondary arm orientable at a first of its ends around the axis parallel to the axis of the first main arm and located between the two ends of the first main arm and closer to its first end,

[0019] - a second secondary arm orientable at a first of its ends around a axis parallel to the axis of the first main arm and located in the vicinity of the second end of the first secondary arm, a second of its ends being orientable around an axis located in the vicinity of the first end of the second main arm, so that the first main arm and the second secondary arm are parallel;

[0020] - a central actuating arm with an axis of symmetry perpendicular to the different axes of rotation of the main and secondary arms comprises a yoke supporting the axis of the first end of the first main arm, this central actuating arm being able to move simultaneously laterally along its axis of symmetry and axially around its axis of symmetry; and,

[0021] - a plate, rotatably mounted around the axis of symmetry of the central arm actuating and supporting the axis of the first main arm in the vicinity of the central body.

[0022] Advantageously, the actuation modules for generating translational and rotational movements of the central actuation arm of the actuators will comprise an actuation mechanism for generating translational movements of the central actuation arm, and an actuation mechanism for generating rotational movements of this same central actuation arm, the translation of the central actuation arm being such that the two main arms of the actuators will constitute a V-shape of variable opening, the rotation of the central actuation arm being such that it will generate a variable angle orientation of the actuators. Consequently, the four thrusters each comprising an actuator consisting of articulated arms and an actuator module for generating translational and rotational movements, thus have two degrees of freedom.

[0023] Advantageously, the axes of the central actuating arms will be oblique relative to the main axis of said central body, forming an angle of between 10° and 45°, allowing the optimization of the efficiency of said fin when closing the V-shaped structure.

[0024] Advantageously, the palm-shaped structure located in the vicinity of the second end of the second main arm will be such that its deformation is on the one hand located in the vicinity of a plane parallel to the main axis of the central body, the V-shaped structure being in the extended position, and on the other hand located in the vicinity of a plane perpendicular to the main axis of the central body, the V-shaped structure being in the flexed position.

[0025] Advantageously, the movement of the V-shaped structure, from the position extension to flexion position will be of shorter duration than the duration of the movement of the V-shaped structure from flexion position to extension position.

[0026] Of course, the mechanical design of the platform will be such that its density is preferably very slightly lower than the density of the aquatic environment. Its density will advantageously be between 1 and 0.8 times, and preferably between 0.998 and 0.996 times, the density of the aquatic environment.

[0027] Synchronous movements of the four propellers according to their respective V-shaped opening on the one hand and according to their orientation around the axis of the respective central actuating shaft on the other hand, will allow the platform in an aquatic environment:

[0028] - to perform vertical dives,

[0029] - to maintain a stationary state,

[0030] - to orient itself in heading around the main axis of the central body,

[0031] - to move forward and backward, and

[0032] - to move to starboard and port.

[0033] The movement of the central actuating arm along its main axis makes it possible to modify the opening of the V-shaped structure; in the present case, the displacement movements of the four arms will be synchronous, however the amplitude of the displacement will be variable depending on the thruster, thus making it possible to modify the opening of each of the V-shaped structures.

[0034] The vertical ascent of the platform will be carried out naturally thanks to Archimedes' thrust given its density preferably between 0.998 and 0.996 times the density of the aquatic environment.

[0035] Synchronous movements of the four thrusters according to their respective V-shaped opening on the one hand and according to their orientation around the axis of the respective central actuating shaft on the other hand, will also allow the platform on land:

[0036] - to move forward and backward, and

[0037] - to move left and right.

[0038] Advantageously, the platform will be equipped with a device for transmitting information between said autonomous platform and a control / command station, as described in French patent FR 2 792 478 published on July 13, 2001. This mode of transmitting information via an optical fiber, operating in “full duplex” meets the bandwidth requirements imposed for the real-time transfer of video images.

[0039] Furthermore, the platform will advantageously be equipped with a 9-degree-of-freedom inertial unit making it possible to stabilize the horizontal attitude of the platform and to take into account the direction of magnetic north; it will thus define the direction nominal direction of travel and consequently the allocation of the names "starboard front", "starboard rear", "port front" and "port rear" of the four thrusters arranged in a star around the central body; the platform will also include a computer architecture to respond to the problems of control / command, localization and perception of the environment of objects evolving in 3D, with algorithms corresponding to the constraints linked to the limited carrying capacities, and to the interfacing of the sensors necessary for the mission; in this configuration, the platform will be autonomous, the aquatic routes on the surface and in immersion will be pre-programmed and associated with geo-localized points; similarly the platform will be autonomous, the routes on land will be pre-programmed and associated with geo-localized points.

[0040] Advantageously, the platform, intended to evolve in an aquatic environment and on land, will be energetically autonomous, thanks to batteries with a high stored energy density.

[0041] An embodiment of the invention will be described below, by way of non-limiting example, with reference to the appended drawings in which:

[0042] [Fig-1] is a schematic representation of a platform according to the invention in flex configuration;

[0043] [Fig.2] is a schematic representation of the platform in configuration extension ;

[0044] [Fig.3] is a schematic representation of the platform in top view;

[0045] [Fig.4] is a sagittal section of an internal structure of the platform in confi flexion structure;

[0046] [Fig.5] is an axial section of an actuation module according to the invention in confi flexion structure;

[0047] [Fig.6] is a cross-section of the actuation module according to the invention in flexion configuration, perpendicular to [Fig.5];

[0048] [Fig.7] is another longitudinal section of the actuation module according to the invention in flexion configuration, perpendicular to [Fig.5] and 6;

[0049] [Fig.8] is a longitudinal section of the actuation module in configuration extension ;

[0050] [Fig.9] is a cross-section of the actuation module in configuration extension, perpendicular to [Fig.8];

[0051] [Fig. 10] is another longitudinal section of the actuation module in confi extension figure, perpendicular to [Fig.8] and 9;

[0052] [Fig. 11] is a schematic elevational representation of an actuator consisting of articulated arms in extension;

[0053] [Fig. 12] is a schematic elevational representation of the actuator in bending;

[0054] [Fig. 13] is a schematic representation in section seen from above of the actuator in extension;

[0055] [Fig. 14] is a schematic representation in section seen from above of the actuator in partial extension;

[0056] [Fig. 15] is a schematic representation in section seen from above of the actuator in partial bending;

[0057] [Fig. 16] is a schematic representation of a first stage of the movement of the platform on earth according to a first mode;

[0058] [Fig. 17] is a schematic representation of a second stage of the movement of the platform on land according to the first mode;

[0059] [Fig. 18] is a schematic representation of a third stage of the movement of the platform on land according to the first mode;

[0060] [Fig. 19] is a schematic representation of a fourth stage of the movement of the platform on land according to the first mode;

[0061] [Fig.20] is a schematic representation of a first stage of the movement of the platform on earth according to a second mode; and,

[0062] [Fig.21] is a schematic representation of a second stage of the displacement of the platform on land according to the second mode.

[0063] In the example shown in Figures 1 and 2, a platform P in particular is respectively in extension configuration and in flexion configuration.

[0064] According to [Fig.l], the platform P, centered around a main axis 100, is essentially made up of a central body C and four thrusters, two of which are shown, PI, P3, which are made up of actuation modules, two of which are shown, MAI, MA3, and of actuators, two of which are shown, A1, A3, associated with the actuation modules, respectively MAI and MA3, each actuating a respective fin PA1, PA3; the other two orthogonal thrusters are not shown in order to facilitate understanding of the structure of said platform.

[0065] The central body C consists of a cylindrical enclosure E supporting the four actuation modules arranged in a star shape and a hemispherical bulb BU, located in the vicinity of the upper part of the central body C.

[0066] The internal structure of the central body C is such that the center of gravity of the platform is close to the lower end of the central body C, and the center of thrust is close to the upper end of the central body C, so that the resultant of these two centers is located below the support zone defined by the four actuators.

[0067] The actuators A1, A3, are rotatably mounted around their respective main axis XI, X3; these said axes XI, X3, are oblique relative to the central axis 100 of the central body C and concurrent with each other and with the central axis; each axis XI-X4 actuator forms the same angle, the apex of which is directed upwards, with the main axis. This angle allows optimization of the efficiency of the fin, preferably between 10° and 45°.

[0068] In [Fig.l], the platform P, being in flexion configuration, the fins PA1, PA3 associated respectively with the actuators A1, A3, are in a plane located in the vicinity of a horizontal plane, and positioned above a respective support SPA1, SPA3, formed of rigid structures with fine meshes. These structures, in the position of [Fig.l], allow water to pass through the meshes.

[0069] According to [Fig.2], the platform P, centered around the central axis 100, consisting of the central body C, the four actuation modules, two of which are represented, MAI, MA3, of four actuators, two of which are represented, A1, A3, associated with the actuation modules, respectively MAI and MA3, being in the extension configuration, the fins PA1, PA3 associated respectively with the actuators A1, A3, are in a plane located in the vicinity of a vertical plane, and positioned against their respective support SPA1, SPA3. In this position, the structures SPA1, SPA3, serve as support for the fins and provide them with a rigidity capable of opposing the pressure of the water.

[0070] Thus, synchronous movements of the four actuators A1, A2, A3, A4, associated respectively with their actuation modules MAI, MA2, MA3, MA4, which are arranged in a star shape around the central body C, according to their respective V-shaped opening, will allow the platform P to dive vertically.

[0071] Indeed, the platform P being in extension configuration, the fins PA1, PA3 associated respectively with the actuators A1, A3, are in a plane located in the vicinity of a horizontal plane and perpendicular to the central axis 100 of the central body C.

[0072] According to a diving cycle, the actuation modules, respectively MAI, MA3, perform a rapid translational movement towards the center of the central body C, which generates the flexion configuration, illustrated in [Fig.l], the fins PA1, PA3, are then in a plane located in the vicinity of a horizontal plane.

[0073] Prior to this diving cycle, the actuation modules A1, A2, A3, A4, perform a rapid rotation movement in the clockwise direction according to the arrow F for the two actuators A1 and A3 arranged along a first diagonal and a rapid rotation movement in the counterclockwise direction according to the arrow F not shown for the two actuators A2 and A4, not shown, arranged along the second diagonal.

[0074] During this diving cycle allowing the transition from the extension configuration to the flexion configuration, the fins PA1, PA3 generate a vertical upward thrust, causing the platform to dive; moreover, the quantity of movement associated with this vertical displacement allows a so-called reconfiguration cycle, described below. According to this reconfiguration cycle, the actuation modules, respectively MAI, MA3, perform a slow translational movement in the opposite direction, which generates the extension configuration, the fins PA1, PA3, are then in a plane located in the vicinity of a vertical plane at the end of the stroke, illustrated in [Fig.2]; during this reconfiguration cycle, the fin, being flexible, undergoes a deformation under the pressure of the water, thus offering less resistance to the movement of the actuator, as illustrated in [Fig.l].

[0075] Prior to this reconfiguration cycle, the actuation modules A1, A2, A3, A4, perform a rapid rotation movement in the counterclockwise direction according to the arrow F for two actuators A1 and A3 arranged along a first diagonal and a rapid rotation movement in the clockwise direction according to the arrow F not shown for the two actuators A2 and A4, not shown, arranged along the second diagonal.

[0076] In the example shown in [Fig.3], the platform P in top view, centered around the main axis 100, is made up of the central body C represented by the cylindrical enclosure C, the four actuation modules MAI, MA2, MA3, MA4, the four actuators A1, A2, A3, A4, associated with said actuation modules, respectively MAI, MA2, MA3, MA4, being in flexion configuration and the fins PA1, PA2, PA3, PA4, associated respectively with said actuators A1, A2, A3, A4.

[0077] The direction of travel, indicated in said [Fig.3], defined by the positioning of said inertial unit, determines the allocation of the names “starboard front”, “starboard rear”, “port front” and “port rear” of the four thrusters PI, P2, P3, P4, arranged in a star around the central body C.

[0078] In the example shown in [Fig.4], the platform P is represented according to a sagittal section at the level of the thrusters PI, P3, located around the central body C, indicated by its external envelope of the cylindrical enclosure E.

[0079] The platform P, being in flexion configuration, the fins PA1, PA3 associated respectively with the actuators A1, A3, are in a plane located in the vicinity of a horizontal plane.

[0080] The actuation modules MAI, MA3, making it possible to generate translational and rotational movements of the central actuation arm of each of the actuators A1, A3, are integral with the central body C, making it possible on the one hand to deform said palm-shaped structure PA1, PA3, according to a variable opening and on the other hand to perform a rotation of said palm-shaped structure around the main axis XI, X3 of said central actuation arm.

[0081] The actuation modules MAI, MA3, comprise different mechanical members which will be represented and described in figures 5 and 6; they each comprise respectively two servomotors SM1-1, SM 1-2 and SM3-1, SM3-2.

[0082] In the example shown in Figures 5, 6, 7, an actuation module MA, in flexed configuration, is shown in a longitudinal section ([Fig.5]), in a cross-section ([Fig.6]), and according to a top view ([Fig.7]).

[0083] According to figures 5, 6, a crown with internal teeth CO of primitive diameter D, centered on an axis X5, is shown schematically in section in figures 5, 6.

[0084] An externally toothed pinion PI with primitive diameter D / 2, centered on an axis X6 of a shaft AO, constituting a satellite inside the aforementioned internally toothed crown CO, is shown in section in Figures 5, 6, its axis X6 being distant by D / 4 from the axis X5.

[0085] Said internally toothed crown C0 and said externally toothed pinion PI have an identical tooth module.

[0086] Said externally toothed pinion PI is driven in a circular movement according to a circle of diameter D / 2, around the shaft A0, centered on the axis X5, and secured to a plate PO, which is secured to a shaft Al, centered on the axis X5, said shaft Al is secured to the drive axis of a servomotor SMI.

[0087] A circular plate C1, rotating around the externally toothed pinion P1, centered on the axis X6, comprises a shaft A2, centered on an axis X7; said axis X7 is distant by D / 2 from the axis X6.

[0088] A rectangular partition CL constitutes the sealed connection between the internal mechanism of the actuation module MA and the casing of said actuation module MA, which is integral with the central body C (not shown).

[0089] A horizontal sole SE, secured to the vertical partition CL, makes it possible to secure said servomotor SMI, and on the other hand a servomotor SM2 as well as a support SU of the aforementioned internal toothed crown C0.

[0090] Thus, as shown in [Fig.5], the rotational drive around the axis X5 of the externally toothed pinion PI shown in section causes it to rotate on itself around its axis X6, which axis X6 consequently describes a circle of diameter D / 2 around the axis X5; a point Q, not shown, located on the primitive circle of the externally toothed pinion C0, at the level of the axis X7, moves along an axis X8 with a total amplitude equal to D, primitive diameter of the internally toothed crown C0, on either side of the axis X5.

[0091] This is a connecting rod / crank type movement, transforming the rotational movement carried out by the shaft A1 of the SMI servomotor into a back and forth movement of the shaft A2.

[0092] Thus, in the example shown in figures 5, 6, 7, the actuation module MA is in flexion configuration, the axes X6, X7, are to the left of the axis X5, distant respectively by D / 4 and D / 2 from the point Q indicated in [Fig.7].

[0093] Furthermore, a central actuating arm B0, of circular section, is driven in translation by means of the axis A2 along the axis X8. The central arm B0 is rotatably mounted along the axis X8 at the center of a hub MO; the internal end of said hub MO is secured to a pinion P3, which is driven by a pinion P4 secured to the shaft A3 of a servomechanism SM2, which is secured to the horizontal sole SE.

[0094] A first seal Jl, located at the end of said hub MO, in the vicinity of the central shaft B0, ensures the sealing of the central actuating arm B0; a second sealing joint J2, located at the end of said hub MO, located on the internal periphery, ensures the sealing between said hub MO and the casing of said actuating module MA, which is integral with the central body C (not shown).

[0095] The actuation module therefore has two degrees of freedom: the translation of the central actuation arm B0 along the axis X8 and the rotation of the hub MO around the same axis X8.

[0096] In the example shown in Figures 8, 9, 10, the actuation module MA, in extension configuration, is shown in a longitudinal section ([Fig.8]), in a transverse section ([Fig.9]) and in a top view ([Fig. 10]).

[0097] Thus, as shown in Figures 8, 9, the rotational drive of the externally toothed pinion PI, centered on the axis X6 of the shaft A0, causes it to rotate on itself around its axis X6, which axis X6 consequently describes a circle of diameter D / 2 relative to the axis X5; the point Q, indicated in [Fig. 10], located on the pitch circle of the internally toothed crown C0, moves along the axis X8 by a total amplitude equal to D, the pitch diameter of the internally toothed crown C0, on either side of the axis X5.

[0098] Thus, in figures 8, 9, 10, the actuator module MA is in extension configuration, the axes X6, X7, are to the right of the axis X5, distant respectively by D / 4 and D / 2 from the point Q indicated in [Fig. 10].

[0099] Advantageously, the aforementioned internally toothed crown C0 may comprise 100 teeth of module 0.4; the aforementioned externally toothed pinion PI may comprise 50 teeth of module 0.4; the aforementioned servomotor SM may be either of the stepper motor type capable of comprising 200 steps per revolution, or a positioning servomotor with an amplitude of + / - 90 degrees.

[0100] Advantageously, different configurations concerning the operation of the stepper motor can be envisaged, namely:

[0101] - the so-called “half step” mode allows you to double the duration of the steps and divide by 2 the stroke carried out by the stepper motor; this configuration will be intended to allow the platform to rise to the surface while ensuring the stability of its attitude;

[0102] - the so-called “partial” mode allows you to run a race, not 100 steps like indicated previously, but a run of 60 steps or 80 steps, for example, centered around the fiftieth step; this configuration will be intended to avoid dead spots so-called "top dead center and bottom dead center" characterizing any connecting rod / crank device;

[0103] - the so-called "Gaussian" mode allows a stroke to be carried out, not step by step in duration constant, but of variable duration during the cycle; the duration of the step gradually decreasing towards a minimum value in the middle of the cycle to gradually increase until the end of the cycle; this configuration will be intended to allow a more harmonious movement of the actuator and in particular to reduce aquatic disturbances when starting and stopping the movements of the actuator.

[0104] In the example shown in Figures 11, 12, 13, 14, 15, the actuator A is shown in profile view in extension configuration ([Fig.11]), in flexion configuration ([Fig. 12]), in top view in deployed extension configuration ([Fig. 13]), in partial extension configuration ([Fig. 14]), and in partial flexion configuration ([Fig. 15]).

[0105] The actuator A, according to figures 11, 13, comprises:

[0106] - a PLA plate, integral with said MO hub previously described, rotatably mounted around an axis X8, and comprising two seats COa and COb, mounted integrally with the PLA plate, and symmetrically around the axis X8, which seats COa and COb respectively support the axes X9a and X9b,

[0107] - a first main arm consisting of two arms Bla and Blb, a central arm Blc, and a hub Cl constituting the axis X10, the two arms Bla and Blb being rotatably mounted around the axes X9a and X9b respectively in the vicinity of their first end and are secured, in the vicinity of their second end, to the hub Cl constituting the axis X10, the central arm Blc being secured, in the vicinity of its first end, to the hub Cl, and secured, in the vicinity of its second end, to a hub C3 constituting the axis XI1; note that said hub C3 is not shown in [Fig. 15] (deployed configuration),

[0108] - a second main arm consisting of a central arm B2a, two arms B2b and B2c, and a hub C5 constituting the axis X14, the central arm B2a being rotatably mounted around the axis X12 in the vicinity of its first end, and rotatably mounted, in the vicinity of its second end, to a hub C4 constituting the axis X13, the two arms B2b and B2c being secured, in the vicinity of their first end, to the hub C4 and secured, in the vicinity of their second end, to a hub C5 constituting the axis X14,

[0109] - a first secondary arm consisting of two arms B3a and B3b, mounted to rotate around the axis X10, in the vicinity of their first end, and mounted to rotate around the axis XI1, in the vicinity of their second end,

[0110] - a second secondary arm consisting of two arms B4a and B4b, mounted to rotate around of the axis XI1 of a hub C3, in the vicinity of their first end, and mounted to rotate around the axis X13 of the hub C4, in the vicinity of their second end,

[0111] - said central actuating arm B0, mounted to rotate and slide around the axis X8, and comprising a CH yoke in the vicinity of its second end, which CH yoke supports the XI1 axis formed by the hub C2; note, for reasons of ease of representation, the CH yoke is shown separate from the hub C2, which explains the presence of two XI1 axes.

[0112] Actuator A, according to [Fig.12], is shown in a profile view in flexed configuration.

[0113] The actuator A according to figures 14, 15, is shown in top view respectively in extension configuration and in flexion configuration, thus making it possible to indicate the position of the yoke CH secured to the hub C2.

[0114] Thus the axial translation of the central actuating arm B0 along the axis X8 makes it possible to modify the position of the hub C2 and consequently to deform the structure of the pantograph, namely:

[0115] - said central actuating arm B0 being in the withdrawn position, the actuator A will be in flexed configuration, and

[0116] - said central actuating arm B0 being in the advanced position, the actuator A will be in extension configuration.

[0117] The transition from the extension configuration to the flexion configuration will allow the generation of an upward vertical force and consequently will cause the platform according to the invention to dive, thanks in particular to the first deformation of the end fin in the vertical position towards the horizontal position; the quantity of movement generated by this movement will then allow the transition from the flexion configuration to the extension configuration, facilitated by the second deformation of the end fin in the horizontal position towards the vertical position, thus offering less resistance to the aquatic environment. The resulting forces, applied to the platform, will therefore be essentially parallel to the main axis of the central body and predominantly vertical.

[0118] Furthermore, the inclination around the X8 axis of the PLA plate, which drives the entire V-shaped structure, will make it possible to create a component normal to the resulting vertical forces; this normal component may be of variable magnitude and in the opposite direction depending on the value and direction of the angle of inclination around the X8 axis of the PLA plate.

[0119] In the example shown in Figures 16, 17, 18, 19, the platform P is schematically shown moving on land according to a first four-stage propulsion mode; according to the first stage, shown in [Fig. 16], the thrusters, only shown starboard / front TR / AV and port rear BA / AR, are in the flexed position, the platform P being in the initial position; according to the second stage, shown in [Fig. 17], the starboard / front TR / AV thruster remains in the flexed position, and the port rear BA / AR thruster is in the extended position, the platform P being in the rearwardly inclined position; according to the third stage, shown in [Fig. 18], the starboard / forward thruster TR / AV remaining in the flexed position, the rear port thruster BA / AR is in the flexed position, the platform P remaining in the rearward inclined position; according to the fourth step, shown in [Fig. 19], the starboard / forward thruster TR / AV makes a rapid transition from the flexed position to the extended position, the rear port thruster BA / AR remains in the flexed position, the platform P makes a jump to the left, then finds itself in the initial position shown in [Fig. 16] by placing the starboard / forward thrusters TR / AV and rear port thrusters BA / AR in the flexed position.

[0120] This method of propulsion on land is particularly suitable in the presence of obstacles or sloping terrain; in this case, according to [Fig. 16], the starboard / front TR / AV and port rear BA / AR thrusters will be in the flexed or semi-flexed position so as to position the platform P vertically.

[0121] The direction of movement, according to this first mode, is defined by the choice of the propeller making the rapid transition from the flexion position to the extension position; thus the jumps made by the platform can be directed in four directions.

[0122] In the example shown in Figures 20, 21, the platform P is shown schematically moving on land according to a second propulsion mode; according to the first step, shown in [Fig.20], the platform being shown in top view, the thrusters, starboard / front TR / AV, starboard rear TR / AR, port front BA / AV, and port rear BA / AR, are in the flexed position, the platform P being in the initial position; the direction of travel is designated by the associated arrow and corresponds to the direction of a diagonal shown in [Fig.21]; according to the second step, shown in [Fig.21], the thrusters, starboard / front TR / AV, starboard rear TR / AR, port front BA / AV, and port rear BA / AR, perform a rotation of the fins PA1, PA2, PA3, PA4, according to the corresponding arrows F, the platform P performs a movement according to the direction of travel previously defined, the rotations according to the arrows F of said fins PA2, PA3, are performed in the clockwise direction, the rotations according to the arrows F of said fins PA1, PA4, are performed in the counterclockwise direction; the movement of the platform P being carried out, the rotations according to the arrows F of said fins PA2, PA3, are performed quickly in the counterclockwise direction, the rotations according to the arrows F of said fins PA1, PA4, are performed quickly in the clockwise direction, so that the platform P is in the initial position as shown in [Fig.20].

[0123] This mode of propulsion on land is suitable for flat terrain, in the absence of obstacles; thus the movements made by the platform P can be directed in four directions; moreover, turns to the left or to the right can be made depending on the amplitude of the rotations of the fins PA1, PA2, PA3, PA4.

Claims

Claims

1. Mobile platform (P), preferably energetically autonomous, capable of moving in water and / or on land, in particular to carry out underwater and / or land reconnaissance, characterized in that it comprises: a central body (C), with a central axis (100); and at least three, preferably four, thrusters (PI, P2, P3, P4) arranged around said central body; each thruster comprising: an actuator (A1, A2, A3, A4), provided, at a distal end (B2), with a fin (PA1, PA2, PA3, PA4); and, an actuation module (MAI, MA2, MA3, MA4) integral with said central body and having a main axis (XI, X2, X3, X4) preferably oblique to said central axis (100) and designed to generate a rotation of said actuator around the main axis and a deformation of said fin, this actuator comprising articulated arms in the form of a pantograph of which a central actuation arm (B0) extends along the main axis (XI, X2, X3, X4), the actuation module being designed to generate a rotation of said central arm around the main axis and a translation of said central shaft along the same said main axis, so that the distal end (B2) forms a more or less large angle with said main axis.

2. Platform according to claim 1, characterized in that each articulated arm comprises: a first main arm (B la, Blb, B le), orientable at a first of its ends, in the vicinity of the central body (C), around an axis (X9); a second main arm (B2a, B2b) orientable at its first end, in the vicinity of a second end of the first main arm (Bla, Blb, B le), around an axis (X12) parallel to an axis (X10) of the first main arm (B la, Blb, B le); a first secondary arm (B3a, B3b) orientable at a first of its ends around the axis (X10) parallel to the axis (X9) of the first main arm (Bla, Blb, Ble) and located between the two ends of the first main arm (Bla, Blb, Ble) and closer to its first end, a second secondary arm (B4a, B4b) orientable at a first of its ends around an axis (XI1) parallel to the axis (X9) of the first main arm (Bla, Blb, Ble) and located in the vicinity of the second end of the first secondary arm (B3a, B3b), a second of its ends being orientable around an axis (XI3) located in the vicinity of the first end of the second main arm (B2a, B2b), so that the first main arm (B1a, B1b, B1e) and the second secondary arm (B4a, B4b) are parallel; a central actuating arm (BO) having an axis of symmetry (X8) perpendicular to the different axes of rotation (X9, X10, X11, X13) of the main arms (B1a, B1b, B1e, B2a, B2b) and secondary arms (B3a, B3b, B4a, B4b), comprises a yoke (CH) supporting the axis (X9) of the first end of the first main arm (B1a, B1b), said central actuating arm (BO) being able to move simultaneously laterally along its axis of symmetry (X8) and axially around its axis of symmetry (X8);and, a plate (PLA), rotatably mounted around the axis of symmetry (X8) of the central actuating arm (BO) and supporting the axis (X9a, X9b) of the first main arm (Bla, Blb) in the vicinity of the central body (C).;

3. Platform according to claim 2, characterized in that the actuation module (MAI, MA2, MA3, MA4) for generating translational and rotational movements of the central actuation arm (BO) of the actuators (A1, A2, A3, A4) comprises a servomotor (SM) for generating translational movements of said central actuation arm (BO), and a servomotor (SM) for generating rotational movements of said central actuation arm (BO), the translation of said central actuation arm (BO) being such that the two main arms (Bla, Blb, Blc, B2a, B2b) of the actuator (A1, A2, A3, A4) constitute a V-shaped structure of variable opening, the rotation of said central actuation arm (BO) being such that it generates a variable angle orientation of the actuator (A1, A2, A3, A4).

4. Platform according to one of claims 2 and 3, characterized in that the axis (X8) of the central actuating arm (BO) is oblique relative to the main axis (100) of the central body (C), forming a variable angle of between 10° and 45°, allowing optimization of the efficiency of the fin (PA1, PA2, PA3, PA4) when closing the V-shaped structure.

5. Platform according to claim 4, characterized in that the palm-shaped structure (PA1, PA2, PA3, PA4) located in the vicinity of the second end of the second main arm (B2), is such that its de- formation either on the one hand located in the vicinity of a plane parallel to the main axis (100) of the central body (C), the V-shaped structure being in the extension position, and on the other hand located in the vicinity of a plane perpendicular to the main axis (100) of the central body (C), the V-shaped structure being in the flexion position.

6. Platform according to one of claims 3 to 5, characterized in that the movement of the V-shaped structure, from the extension position to the flexion position is of shorter duration than the duration of the movement of the V-shaped structure, from the flexion position to the extension position in underwater mission mode.

7. Platform according to one of claims 3 to 6, characterized in that a rapid transition of the V-shaped structure of a thruster from the extension position to the flexion position, the other three thrusters being in the flexion position, allows said platform to perform a jump in the opposite direction to said thruster performing said rapid transition in terrestrial mission mode.

8. Platform according to claim 1 to 6, characterized in that the rotations of the fins (PA1, PA2, PA3, PA4) allow said platform (P) to move in four directions as well as changes of direction in terrestrial mission mode.

Images