EP4061710A1

EP4061710A1 - Drone

Info

Publication number: EP4061710A1
Application number: EP20804577.3A
Authority: EP
Inventors: Dimitry BREGA; Sylvain ROLDAN DE PERERA
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-19
Filing date: 2020-11-17
Publication date: 2022-09-28
Also published as: US20230002045A1; FR3103174B1; US12054255B2; WO2021099334A1; FR3103174A1

Abstract

A drone comprising a front section, a wing structure supported by a rotor located behind the front section, and a propeller at the rear, the wing structure comprising two wings rotating with the rotor, the wing structure being able to move between a flight configuration, in which the rotor is immobile relative to the front section and the propulsion provided by the propeller, and a flight configuration with the wing structure rotating, in which the rotor is rotated relative to the front section, the rotor being connected to the front section with a possibility of orienting its axis of rotation relative thereto in order to be able to direct the drone in the rotary wing structure configuration by acting on said orientation.

Description

DRONE

Technical area

The present invention relates to a drone having a scalable wing, and a corresponding launcher.

Prior art

Application WO 2018/024567 discloses an evolving wing drone, comprising two wings connected to a rotor, the wing being able to evolve between a fast flight configuration where the rotor is stationary relative to the fuselage and a rotary wing flight configuration, where the rotor is driven in rotation relative to the fuselage.

There is a need to further improve this type of drone, in particular to improve its maneuverability in a rotary wing flight configuration.

Disclosure of the invention

The invention aims to meet this need, according to a first of its aspects.

Summary of the invention

The subject of the invention is thus a drone comprising a front part, an airfoil carried by a rotor situated behind the front part, and a propulsion propeller at the rear, the airfoil comprising two wings rotating with the rotor, the airfoil. can evolve between a flight configuration where the rotor is stationary relative to the front part and the propulsion is provided by the propeller, and a flight configuration with rotary wing, where the rotor is rotated relatively to the front part, the rotor being connected to the front part with a possibility of orientation of its axis of rotation relative to the latter in order to be able to steer the drone in rotary wing configuration, playing on said orientation

With the ability to orient the rotor in forward flight in a rotary airfoil configuration, the drone can be steered horizontally, without having to provide complex cyclic pitch control at the link between the wings and the rotor.

The drone comprising a stator carrying the rotor, the stator can be connected by at least one actuator to the front part, the actuator being arranged to modify the orientation of the stator relative to the front part when it is actuated. Preferably, the drone comprises several actuators connecting the front part to the stator and making it possible, when actuated, to modify the orientation of the stator relative to the front part around at least two geometric axes. More preferably, the drone comprises three actuators connecting the front part to the stator, arranged at 120 ° to each other around the longitudinal axis of the stator. These actuators are preferably linear actuators, and are preferably each connected by a ball joint to the stator.

Like a helicopter, the drone according to the invention can have a collective pitch control and a cyclic pitch control. Collective pitch control can be provided by actuators located in the wings. Cyclic pitch control is achieved by tilting the stator. Thus, preferably, the wings can pivot relative to the rotor to change their incidence, which makes it possible to change the collective pitch in the rotary airfoil configuration.

Preferably, the drone has a ball joint between the front part and the stator. Such a connection advantageously makes it possible to take up part of the mechanical forces between the front part and the stator. A deflector advantageously covers this connection, to make it possible to maintain continuity of the fuselage at the transition between the front part and the stator, despite changes in orientation of the latter.

The drone has a motor to rotate the propeller propeller. This engine is preferably housed in the front part, a transmission line connecting the engine to the propulsion propeller, this transmission line comprising a transmission joint making it possible to transmit the drive from the engine to the propulsion propeller despite the orientation changes of the axis of rotation of the rotor relative to the front part. Preferably, the drone is arranged such that the orienting movements of the axis of rotation of the rotor take place around a center of rotation on which the transmission joint is centered.

Preferably, the propeller and the rotor are driven by the same engine. The rotor can be driven via a planetary gear reducer.

The drone may have a rear part carrying the propeller, the rotor rotating between the front and rear parts.

Preferably, each wing is connected to the rotor by a mast comprising an articulation allowing the wing to be folded over the fuselage during a launch phase of the drone, when the latter is contained in a launcher.

More preferably, the drone comprises a mechanism which makes it possible to block the hinge once the wing has been deployed. This locking mechanism may include a locking ring which comes in the locking position to cover the hinge and thus immobilize the mast in a configuration where it is coaxial with the ring. An actuator housed in the wing can generate a relative movement between the mast and the locking ring making it possible to bring the latter into its locking configuration. The variation of the incidence of the wing relative to the rotor can be obtained by a mechanism which transforms a rotational movement of an actuator into an axial displacement of the mast. The latter may include a first lug close to the actuator and a second lug close to the rotor. The two pins move together under the action of the actuator. The latter rotates a drive ring which has an axial slot in which the first lug is engaged. The first lug is also engaged in a helical slot of a tubular part fixed with the wing, integral with the locking ring. Thus, a rotation of the drive ring is accompanied by an axial displacement of the mast relative to the locking ring and to the fixed tubular part. The second lug is engaged in a slot made on a tubular part which is fixed to the rotor, and which rotates with it. This slot has a first portion, which is linear and extends radially, and a second portion which is helical. When the mast moves axially, under the effect of the rotation of the actuator, the second lug moves in the first linear portion, then in the second portion. The first portion serves to lock the wing in the fixed wing advancement configuration. The second portion makes it possible to modify the incidence of the wing in the rotary airfoil configuration, to vary the collective pitch.

Another subject of the invention, according to another of its aspects, independently or in combination with the foregoing, is a launcher that can be used to launch a drone as defined above, comprising a cover capable of housing the drone, and four boosters with vectorial thrust, to orient the launcher.

Preferably, the drone has folding wings, which can be folded back against the fuselage when the drone is contained in the launcher.

Preferably, the fairing comprises two articulated parts which are kept closed by the aerodynamic thrust during the evolution of the launcher at high speed.

Preferably, the drone has folding wings, which can be folded back against the fuselage when the drone is contained in the fairing.

Preferably, each booster comprises a deflector comprising a body which can pivot about a first axis of rotation, this body enclosing an element which can pivot about a second axis perpendicular to the first. The body may in particular be formed of two blocks which are assembled around a toroidal section constituting said element.

Preferably, a redundant actuator system controls the pivoting of the deflector along these two axes of rotation. Brief description of the drawings

The invention may be better understood from reading the detailed description which follows, of a non-limiting example of implementation thereof, and from examining the appended drawing, in which:

[Fig 1] FIG. 1 represents an example of a drone in fast flight configuration with fixed wing,

[Fig 2] FIG. 2 represents the drone of FIG. 1 in a rotary wing configuration,

[Fig 3] Figure 3 is a partial and schematic longitudinal section of the drone of Figures 1 and

2

[Fig 4] Figure 4 shows a detail of the connection between the stator and the front part of the drone, for a given orientation of the axis of rotation of the rotor,

[Fig 5] Figure 5 is a view similar to Figure 4 for a different orientation of the axis of rotation of the rotor,

[Fig 6] Figure 6 is a schematic exploded perspective view of the connection between the stator and the front part,

[Fig 7] Figure 7 is a partial and schematic view of the rotor drive mechanism, [Fig 8] Figure 8 is a partial and schematic view, with longitudinal section, of the mechanism of Figure 7,

[Fig 9] FIG. 9 partially and schematically represents the connection between the wings and the rotor,

[Fig 10] Figure 10 shows a detail of the connection between a wing and the rotor,

[Fig 11] Figure 11 is a view similar to Figure 10 of another embodiment detail,

[Fig 12] Figure 12 illustrates the folding of the wings along the fuselage, for launch,

[Fig 13] FIG. 13 represents an example of a launcher in front view,

[Fig 14] Figure 14 shows the launcher of Figure 13 in side view,

[Fig 15] Figure 15 shows the launcher of Figure 13 in bottom view,

[Fig 16] Figure 16 shows the launcher of Figure 13 in top view,

[Fig 17] Figure 17 shows a detail of the assembly of a deflector,

[Fig 18] Figure 18 partially and schematically illustrates the deflector orientation mechanism, [Fig 19] Figure 19 illustrates the opening of the launcher,

[Fig 20] Figure 20 shows a connector allowing the drone to exchange information with the launcher, when present within it,

[Fig 21] Figure 21 is a longitudinal section, schematic and partial, of the mechanism integrated into the root of a wing,

[Fig 22] represents the wing at the level of its root,

[Fig 23] represents the mechanism of figure 21, from another angle of view,

[Fig 24] is a view similar to Figure 23, from another viewing angle, and

[Fig 25] shows the mechanism of Figures 23 and 24, with the drive ring removed.

detailed description

The drone 1 according to the invention shown in Figures 1 and 2 comprises two movable wings 10 relative to the fuselage 2 between a configuration with fixed wing, corresponding to Figure 1, and a configuration with rotary wing, illustrated in Figure 2.

The drone 1 has, at the rear, a propeller 3 shown schematically in Figure 2 and, at the front, ailerons 3 of duck plane. The rear part 5 of the drone 1 can carry ailerons and / or control surfaces 6.

In the fixed wing configuration, the wings 10 are fixed relative to the fuselage, with an inverted sweep configuration, which allows the drone to evolve like an airplane, in rapid flight. The reverse boom configuration offers a combination of advantages, including fuel efficiency with low drag, optimized lift and payload, improved maneuverability and greater tolerance to stall at very low engine speeds.

In the example shown, the drone's fuselage has a central bay, with a prism section, which contributes to its lift.

In the rotary airfoil configuration, the wings 10 rotate with a rotor relative to the front part 4 of the drone, with opposite incidences. In this configuration, the wings 10 act like helicopter blades. The propeller 3 can then turn in the opposite direction of the wings 10, to serve as an anti-torque. When the drone is in forward flight in a rotary wing configuration, the dorsal ridge of the prism section of the central bay is preferably placed facing the relative wind.

According to a first aspect of the invention, the axis of rotation of the rotor is orientable relative to the front part 4, which makes it possible to control the progress of the drone in the rotary wing configuration.

If we refer more particularly to Figures 3 to 8, we see that the drone 1 comprises a main electric motor 20, preferably of the brushless type, housed in the front part 4, and connected to the propeller 3 by a transmission line 30 comprising a shaft 31.

The front part 4 houses three actuators 40 arranged at 120 ° to each other around the axis of rotation of the motor 20. These actuators 40 are linear actuators in the example considered, and each comprise a rod 41 movable axially relative to the shaft. body 42 of the actuator. The rods 41 are connected at their end by a ball joint 43 to a stator 50, and make it possible to control the orientation of the latter relative to the front part 4.

The stator 50 comprises a peripheral skirt 51 in the form of a portion of a sphere, which forms a ball joint with an internal skirt 60 of corresponding shape of the front part 4.

A deflector 61 mounted on the fuselage of the front part 4 partially covers the peripheral skirt 51 and ensures a certain continuity of the outer surface of the drone 1, for better aerodynamic performance.

The wings 10 are carried by a rotor 70 which can rotate relative to the stator 50.

The motor 20 preferably incorporates an electromagnetic eddy current brake and a rotor positioning sensor such as an optical encoder.

The electromagnetic brake quickly brings the rotor 70 to a stop when it is launched at full power. Its position is continuously determined by the optical encoder, which allows the motor controller to reposition the rotor if necessary.

A transmission mechanism 80 allows the rotor 70 to be driven with the motor 20.

In the example illustrated, this mechanism 80 is of the epicyclic gearbox type, and comprises, as can be seen more particularly in FIG. 7, an internal sun gear 32 constituted by a pinion mounted on the shaft 31, a large ring 81 forming an integral part of the gear. rotor 70, and a planet carrier 82.

The rotor 70 is guided by bearings 84 and 85 carried by the stator 50. When the latter is blocked, the rotation of the shaft 31 drives that of the rotor 70, with a reduction factor. In this case, the propeller 3 rotates in the opposite direction of the rotor 70.

When the planet carrier 82 is free to rotate, the rotor 70 can be locked in rotation.

When the large crown 81 is blocked, only the propulsion propeller 3 is rotated. When the large crown 81 is released, the epicyclic train acts as a reduction gear and drives the wings 10. This sequence is reversible.

Actuators, not shown, make it possible to selectively block the rotation of the planet carrier 82 or of the rotor 70.

The transmission line 30 comprises a transmission joint 33 between the shaft 31 and the motor 20, which makes it possible to transmit the torque of the motor 20 to the shaft 31, while allowing freedom of orientation of the shaft. 31 relative to engine 20.

This transmission joint 33 may be of the constant velocity type, and include, as illustrated in FIG. 6, a cage 34 provided on its inner surface with grooves 35 which house balls 36 ensuring the transmission of torque with an internal ball 37. The cage 34 of the constant velocity joint 33 and the ball joint formed between the skirts 51 and 60 are substantially concentric.

If we refer to Figures 9 to 11, we see that the roots of the wings 10 comprise mats 11 connected to the rotor 70 and each comprising an articulation 12, visible in Figure 10, which allow the wings to be folded over the fuselage. , as shown in figure 12.

A rotary actuator 13 is housed in each wing to modify their incidence in the rotary wing configuration or to block their incidence in the fixed wing configuration.

The two working axes of the roots make it possible to fold down the wings 10 along the fuselage and to adjust their angle of attack. The wings 10 are automatically deployed by the relative wind and their locking is ensured by a locking ring 18 which covers the articulation 12 when the mast 11 is displaced axially relative to this ring 18 by the actuator 13. As can be seen in the figures. Figures 21 to 25 in particular, each ring 18 is in the form of a cylindrical segment integral with its respective wing and provided with a pull reinforcement 17 perpendicular to its end. The reinforcement 17 follows the chord of the roots and fits into the profile of the wing, behind the leading edge. A mechanism transforms a rotational movement of the actuator 13 into an axial displacement of the mast 11. The latter may include a first lug 311 close to the actuator and a second lug 312 close to the rotor. The two pins 311 and 312 move together under the action of the actuator 13. The latter drives in rotation a drive ring 320 which has an axial slot 321 in which the first lug 311 is engaged. The first lug 311 is also engaged in a helical slot 325 of a tubular part 330 fixed with the wing, integral with the locking ring 18. Thus, a rotation of the drive ring 320 is accompanied by a displacement. axial of the mast 11 relative to the locking ring 18 and to the fixed tubular part 330. The second lug 312 is engaged in a slot 340 formed on a tubular part 341 which is fixed to the rotor 70, and which rotates with it. This slot 340 has a first portion 343, which is linear and extends radially, and a second portion 344 which is helical. When the mast 11 moves axially, under the effect of the rotation of the actuator 13, the second lug 312 moves in the first linear portion 343, then in the second helical portion 344. The first portion 343 serves to lock the wing 10 in the fixed wing advancement configuration. The second portion 344 makes it possible to modify the incidence of the wing 10 in the rotary airfoil configuration, in order to vary the collective pitch.

The actuators 13 can be supplied from the rotor by rotary collectors. The actuators can be checked by power lines, for example.

In the rotary airfoil configuration, the asymmetry between the propeller 3 and the rotor 70 is mechanically compensated by the epicyclic gear which adjusts the number of revolutions per minute between the two. Thus the volume of air swept by the propeller 30 is preferably substantially equal to the volume of air swept by the wings 10 rotating with the rotor.

The drone 1 can be launched while being contained with all wings folded, as illustrated in FIG. 12, in a launcher 100 such as that represented in FIGS. 13 to 19.

Preferably, this launcher is capable of maneuvering at high velocity and, during the launch phase, borrows the flight characteristics of a surface-to-air missile.

The launcher comprises a cap 101 of circular section and a cruciform tail 102. The maneuverability and controllability of the launcher are ensured by four 120 boosters arranged symmetrically around the fairing.

The cover 101 comprises two shells, connected below by a joint 103, visible in FIG. 15.

The symmetrical thrust of the four boosters 120 helps to keep the fairing 101 closed until their deceleration phase. Vector thrust optimizes positioning times with a very tight turn between vertical ejection and horizontal flight. Regardless of its maneuverability, the use of vector thrust makes it possible to maintain control of the launcher with three boosters in the event of a failure of one of the boosters.

The four 120 boosters, symmetrically mounted on either side of the fairing, each have two degrees of freedom (vertical and horizontal), resulting in vector propulsion. Each booster is directly connected to a deflector 122 which forces the gases to borrow an toroidal section 123 with an integrated nozzle, visible in FIG. 17, ensuring the horizontal corrections. The vertical corrections are made by the body of the deflector, composed of two blocks 124 which encapsulate the toric section 123. The latter can pivot about an axis of rotation X relative to the body of the deflector formed by the blocks 124. The section 123 is produced. with ends of diametrically opposed axes 127, which are received in corresponding openings of the body of the deflector, these openings being formed by the meeting of notches 126 present on each of the blocks 124.

Each block 124 comprises half-ends of diametrically opposed axes, which form when the blocks 124 are joined together of the ends of axes 128, as illustrated in FIG. 18, making it possible to orient the deflector around an axis of rotation Y perpendicular to the X axis.

Each actuator system 125 of a booster baffle 120 is preferably provided with symmetrical redundancy regarding the control in rotation about both the X axis and the Y axis, ensuring system reliability.

In particular, as illustrated, the body of the deflector can carry two actuators each connected to a respective end of axle 127, in order to control the tilting of the toric section 123 relative to the body of the deflector, and the latter can pivot around the axis Y under the action of two actuators each connected to an end of axis 128 by means of a respective link mechanism 150.

Reliable release is critical to mission success, and load factors on fairing 101 can compromise opening. In order to overcome this risk, the fairing is kept closed at high speed during the tight turns that the launcher is likely to make and during his deceleration phase.

Throughout the flight, the air flow exerts pressure on the convex deflection surface of the fairing and the separation takes place at a controlled velocity during deceleration. The launcher opening velocity is controlled by concomitant measurements of the air pressure, for example using a Pitot tube, and the mechanical pressure exerted on the fuselage, for example by means of a piezoelectric pressure sensor.

Arrived at its programmed position, the fairing 101 opens, as illustrated in Figure 19, and ejects the drone 1 which can continue its flight in fixed wing or rotary wing configuration. Once the mission is completed, the drone 1 can be recovered by an autonomous ground system with which it communicates.

The drone can comprise, as illustrated in FIG. 20, a connector 300 connected to a corresponding connector present on the launcher (not visible) for the exchange of data between the two, and in particular allowing the control of the boosters and the deflectors by the electronics of the drone during the launch phase. When dropping the drone, the connectors separate. The connector 300 may be present on the ventral face of the fuselage.

In a variant, the drone is gyrostabilized by motors equipped with small propellers housed in the fuselage. These motors play no role in the lift of the drone, and their ability is strictly limited to produce anti-torque thrust and create a moment that allows an approach path to be maintained at a given angle during landing. In order to avoid stability problems linked to the pressure differences between the exterior surface of the cell and the interior, the openings can be closed by a circular slide mechanism integrated into the nose of the cell. The mechanism can be passive and the slide can return to its position by gravity. In the event of a reversion of the wing configuration (rotating wing / fixed wing), the extension generated by the slide shifts the center of gravity towards the rear of the platform, thus helping to increase its stability at low engine speeds. At high speed, the slide retracts under the pressure of the relative wind.

Claims

1. Drone (1) comprising a front part (4), an airfoil carried by a rotor (70) located behind the front part, and a propeller (3) at the rear, the airfoil comprising two wings ( 10) rotating with the rotor, the airfoil being able to evolve between a flight configuration where the rotor is stationary relative to the front part and the propulsion provided by the propulsion propeller, and a flight configuration with rotary airfoil, where the rotor is driven in rotation relative to the front part, the rotor being connected to the front part with a possibility of orientation of its axis of rotation relative to the latter in order to be able to steer the drone in the rotary wing configuration by playing on said orientation.

2. Drone according to claim 1, comprising a stator (50) carrying the rotor (70), the stator being connected by at least one actuator (40) to the front part, the actuator being arranged to modify the orientation of the stator. relative to the front part when actuated.

3. Drone according to claim 2, comprising several actuators (40) connecting the front part to the stator and allowing, when actuated, to modify the orientation of the stator relative to the front part about at least two geometric axes.

4. Drone according to claim 3, comprising three actuators (40) connecting the front part to the stator, arranged at 120 ° to each other around the longitudinal axis of the stator.

5. Drone according to any one of claims 2 to 4, comprising a ball joint (51, 60) between the front part (4) and the stator (50).

6. Drone according to any one of the preceding claims, comprising a motor (20) for rotating the propulsion propeller, this motor being housed in the front part (4), a transmission line (30) connecting the motor. to the propulsion propeller, this transmission line comprising a transmission joint (33) making it possible to transmit the drive of the engine to the propulsion propeller despite the changes in orientation of the axis of rotation of the rotor relative to the front part.

7. Drone according to claim 6, the orientation movements of the axis of rotation of the rotor (20) taking place around a center of rotation on which the transmission joint (33) is centered.

8. Drone according to any one of the preceding claims, the wings (10) being able to pivot relative to the rotor to change their incidence.

9. Drone according to any one of the preceding claims, the propulsion propeller (3) and the rotor (70) being driven by the same motor (20).

10. Drone according to any one of the preceding claims, comprising a rear part (5) carrying the propeller, the rotor (70) rotating between the front (4) and rear (5) parts.

11. Drone according to any one of the preceding claims, each wing being connected to the rotor by a mast (11) comprising an articulation (12) allowing the wing to be folded over the fuselage during a launch phase of the drone, when the latter is contained in a launcher (100), the drone comprising a mechanism which makes it possible to block the hinge (12) once the wing has been deployed, this blocking mechanism preferably comprising a locking ring (18) which comes into the position of locking cover the hinge (12) and thus immobilize the mast in a configuration where it is coaxial with the ring, an actuator (13) preferably housed in the wing allowing to generate a relative movement between the mast and the locking ring allowing to bring it into its blocking configuration.

12. Drone according to any one of claims 8 to 11, the variation of the incidence of the wing relative to the rotor being obtained by a mechanism which transforms a rotational movement of an actuator (13) into an axial displacement of the rotor. mat, the latter preferably comprising a first lug (311) close to G actuator (13) and a second lug (312) close to the rotor (70), the two lugs moving together under the action of the actuator (13) ), the latter rotating a drive ring (320) which has an axial slot (321) in which the first lug (311) is engaged, the first lug (311) also being engaged in a helical slot (325) of a tubular part (330) fixed with the wing, integral with the locking ring (18), a rotation of the drive ring (320) accompanied by an axial displacement of the mast (11) relative to the locking ring (18) and to the fixed tubular part (330), the second lug (312) being engaged in a slot (340) formed on a tubular part (341) which is fixed to the rotor, and which rotates with it, this slot (340) comprising a first portion (343), which is linear and extends radially, and a second portion (344) which is helical.

13. Launcher in which is disposed a drone according to any one of the preceding claims, the drone (1) comprising folding wings, which can be folded against the fuselage when the drone is contained in the launcher.

14. Launcher according to the preceding claim, the launcher comprising a cap housing the drone, and four vector thrust boosters, to orient the launcher.

15. Launcher according to claim 14, the cover comprising two articulated parts which are held closed by the aerodynamic thrust during the development of the launcher at high speed.

16. Launcher according to one of claims 14 and 15, each booster comprising a deflector comprising a body capable of pivoting about a first axis of rotation, this body enclosing an element capable of pivoting about a second axis perpendicular to the first, the body preferably being formed of two blocks (124) which are assembled around a toroidal section (123) constituting said element, a system of redundant actuators preferably ensuring the control of the pivoting of the deflector along these two axes of rotation.