The invention relates to piloting devices used by the pilot in an aircraft cockpit. It relates in particular to an active stick including an integrated force feedback to assist the pilot.

TECHNOLOGICAL BACKGROUND

A piloting device in an aircraft cockpit comprises, in the usual way, a piloting stick with in particular a control lever rotatably mounted about a so-called roll axis and a so-called pitch axis, these two axes being orthogonal to each other. the other. Most often, devices of the "broomstick" type are encountered.

Depending on the position of the lever along these two axes, the piloting device transmits movement commands to the piloting members of the aircraft.

On the most recent models of aircraft, the control of the movements of the aircraft is electronic and the piloting device integrated into the cockpit can be of the "side stick" type. The position of the lever along the two roll and pitch axes is measured by sensors and translated into movement commands. The lever is not directly mechanically linked to the moving parts of the aircraft. There is no direct mechanical feedback on the lever for the pilot.

However, it is desirable for flight safety for the pilot to perceive a mechanical feedback at the level of the lever. Cockpit signaling systems may not be sufficient to cause the pilot to react quickly enough to unforeseen events during flight. The piloting sensations are much better if the mini-control stick incorporates a force feedback, also called "haptic feedback".

It has been proposed as such to equip the sidestick with passive mechanical systems, such as spring systems, or active electromechanical systems.

Furthermore, it has been proposed in document FR 3 01 1 815 to use an active force feedback device with an electric motor. Typically, in this document, the aircraft flight control device comprises a control lever mounted on a plate and connected to a roll axis motor and a pitch axis motor via shafts. transmission. The two motors are controlled according to a law of effort, so as to generate a resistive force opposing the force exerted on the lever (force feedback) when a force threshold is exceeded by the pilot.

Such a device is effective in restoring the sensations of piloting and increasing flight safety. However, in the event of an electrical or mechanical failure in one of the motors or in the event of a failure in the motor control signal processing chain, the force feedback can be suppressed.

In the field of aeronautics, the requirements for the availability of piloting devices are high. It is therefore not acceptable for the pilot to suddenly switch to a control mode without force feedback, in the event of an engine failure or its processing chain.

In addition, state-of-the-art active force feedback systems often include a significant number of components, including roll and pitch motors, but also clutches, torque limiters, gears, and more. These systems can be expensive, bulky, and difficult to integrate into an aircraft cockpit.

SUMMARY OF THE INVENTION

In view of the above, there is a need for a control stick incorporating a mechanical emergency channel, to prevent the rotation of the lever from being free and the pilot from losing all force feedback, in the event of an electrical failure. affecting a force feedback motor.

The desired stick must not be able to switch, in the event of a failure affecting said engine, in a mode in which the pilot freely pivots the lever.

There is a secondary need for a control stick in which, in the event of a failure affecting said motor, the lever is not completely immobilized and the pivoting movements of the lever are damped.

Preferably, the desired mechanical emergency channel provides a variable resistive force depending on the position of the lever relative to a neutral point, in the event of a failure affecting the force feedback motor.

We are also looking for a mini-handle with less mass, bulk and power consumption compared to the existing one.

As such, according to a first aspect, the invention relates to a force application device for a pilot stick of an aircraft, in which the pilot stick comprises a control lever connected to at least one motor comprising a drive shaft movable in rotation about an axis, the force application device comprising:

- a first pawn, connected to the tree,

- a housing, configured to be fixed relative to the aircraft, - an electromagnet,

- an actuator movable relative to the housing, said actuator comprising a magnetic material,

- a coupling device comprising a meshing input nt, connected to the housing, and an output mesh configured to cooperate with the input mesh,

said output meshing comprising a second pin,

- means for tightening the first pin and the second pin, said clamping means comprising a first tooth and a second tooth configured to tighten the first pin and the second pin,

the force application device having an operating configuration, in which the electromagnet is active and the output meshing is positioned at a distance from the input meshing so that the second pin is movable in rotation around the axis, and a blocking configuration, in which the electromagnet is inactive and the output mesh is engaged with the input mesh so as to block the second pin in rotation relative to the housing.

In particular, the force application device is advantageously in accordance with claim 1.

A first advantage of the invention is to provide a mechanical escape route to prevent the lever from being completely free in its pivoting movement. In the event of a failure affecting the motor, the electromagnet is no longer active and the force application device assumes a blocking configuration.

Resistant torque, opposing rotation of the first pin relative to the housing, is exerted on the first pin when the force application device is in the locked configuration. Indeed, the clamping means comprise teeth which clamp the first pin and the second pin, the second pin being integral in rotation with respect to the housing. The drive shaft is then braked in its rotational movement.

An advantage of the invention is that the mechanical emergency channel provided by the force application device is reversible, the force application device being able to adopt an operating configuration again when the electromagnet is at new asset. The relative position of the meshes is controlled via the electromagnet to alternate between the operating configuration and the blocking configuration. This alternation is possible on the ground as well as in flight.

A second advantage is to avoid a complete immobilization of the drive shaft associated with the motor, when an electrical failure affects the motor and when the electromagnet is no longer active. Indeed, the clamping means do not necessarily completely block a rotation of the first pin relative to the second pin.

The force application device of the invention tends to return, when it is in the blocking configuration, the first pin to a position which depends on the position of the second pin at the time of inactivation of the electro magnet. The second pin being movable in rotation around the axis in the operating configuration, it is possible that the position of the second pin during this inactivation is not in correspondence with a central position of the lever.

The stress application device of the invention may have the following optional and non-limiting characteristics, taken alone or in any of the technically possible combinations:

- the actuator is mounted on the input gear.

- the electromagnet is mounted on the housing, so that the actuator is in an axial position between the electromagnet and the output meshing along the axis.

- the device comprises return means comprising a first end fixed to the housing and a second end fixed to the mesh

input, the return means being configured to move the input mesh along the axis.

one of the input meshing and the output meshing comprises at least one tooth, the other among the input meshing and the output meshing comprising at least one complementary housing, the tooth being configured to enter the complementary housing in the blocking configuration.

the clamping means comprise a first jaw and a second jaw, the device further comprising an elastic connection in compression, such as a compression spring, connecting the first jaw and the second jaw so as to urge the first tooth and the second tooth against the first pin and the second pin in operating configuration.

- The device further comprises an angular displacement sensor configured to acquire a measurement of angular displacement of the shaft.

- The device further comprises a damping piece extending over a contact surface between the first pin and the second pin.

- the device further comprises a disengaging device configured to disengage the input meshing and the output meshing, said device comprising a second supply circuit distinct from a standard supply circuit of the electromagnet , in order to allow a disengagement of said cracks when the standard power supply circuit of the electromagnet has failed.

- said output meshing is connected to the actuator.

According to a second aspect, the invention relates to a control stick of an aircraft comprising a control lever, comprising at least one motor which has a drive shaft movable in rotation about an axis, and further comprising a device for application of force as defined above by motor.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics, aims and advantages of the present invention will become more apparent on reading the detailed description which follows,

accompanied by the accompanying drawings given by way of non-limiting examples and in which:

[Fig.1] functionally represents the overall architecture of a piloting system comprising a pilot stick according to one embodiment;

[Fig.2] is a perspective view of the aircraft control lever and the mechanical seal of the system of Figure 1;

[Fig.3] is a side view of the lever of Figure 1 incorporating a force feedback device;

[Fig.4] is a schematic side view of an interface between a motor shaft and a housing comprising a force feedback device according to one embodiment of the invention, seen in an operating configuration without electrical failure. ;

[Fig.5] is a schematic side view of the engine / housing interface including the force feedback device of Figure 4, viewed in a locked configuration in the event of an electrical failure.

DETAILED DESCRIPTION OF EMBODIMENTS

The following examples relate to a force application device intended to operate with a pilot lever which rotates along roll and pitch axes. The invention, however, applies with the same advantages to a rotary lever along any number of axes.

In the description below and in the appended figures, similar elements are associated with the same alphanumeric references.

Overall architecture of the control system

Figures 1 to 3 show a piloting system of an aircraft, comprising a piloting stick, according to an exemplary embodiment.

The handle is typically found in the cockpit of the aircraft. The joystick can be used by the pilot of the aircraft to control moving parts of the aircraft electronically.

In Figure 1, the solid thick lines between two functional units correspond to mechanical links, the arrow links with thick lines

represent a mechanical or magnetic coupling of two units (with possible disconnection) and the arrow links with thin lines are electronic links allowing data transmission.

The piloting stick comprises a control lever 1, mounted to rotate relative to a frame 2. The force application device comprises a mechanical seal 10. The lever 1 is rotatable along a roll axis X and a roll axis Y. pitch, the two axes being orthogonal. The mechanical seal 10 is fixed to a frame 2 integral with the floor of the cockpit of the aircraft.

In the present example, the control stick comprises an electric motor 3a comprising an A-axis drive shaft linked to the X axis of roll of the lever. By “linked to the axis” is meant that a connecting mechanism exists between the shaft of axis A and an element of the joint 2 set in motion when the lever pivots along the axis X. Likewise, the handle comprises an electric motor 3b comprising a drive shaft of axis B linked to the pitch Y axis of the lever.

Alternatively, the motor 3a could be arranged to act directly on the X axis via a rotating shaft linked to the seal 10 and the motor 3b could be arranged to act directly on the Y axis via a rotating shaft linked to the seal 10.

Motors 3a and 3b are configured to apply force to their respective driveshaft. Preferably, the force applied by the motors is calculated according to a force law, depending on the position of the lever.

To acquire the position information of the lever, the handle preferably includes sensors for the angular displacement of the lever. Said sensors preferably include a sensor 11a associated with the roll axis and a sensor 11b associated with the pitch axis. Said sensors communicate electronic position signals to a computer 12.

According to one example, the sensors 11 a and 11 b acquire a rotary position of the drive shafts, respectively along the axes A and B.

The computer 12 includes an electronic interface with the sensors. It can thus receive acquired data of angular displacement of the lever. Optionally, the sensors 11 a and 11 b are also configured to communicate to the computer 12 information on the speed of rotation of the lever 1 according to their associated axes.

The lever position / speed information is translated into steering control signals. mobile parts of the aircraft by a flight control unit 13, or FCS for "Flight Control System", of the aircraft.

Optionally, the control stick includes force sensors 15a and 15b associated respectively with the X roll axis and the Y pitch axis of the lever.

Said sensors are configured to measure the torque exerted on the pivoting lever along the X axis and along the Y axis. The force sensors 15a and 15b are typically strain gauges, for example of the capacitive or piezoelectric type.

Such force sensors are particularly useful if the system includes a force control mode, in addition to a displacement control mode, of which operating examples will be described in relation to the embodiments below. In a force piloting mode, the lever 1 is immobilized and the control unit 8 determines control signals for the moving parts of the aircraft as a function of the forces applied to the lever 1 by the pilot.

The view of Figure 1 illustrates, in addition to the elements described above, a plurality of elements of force application devices, which will be described below.

In one embodiment, illustrated in the accompanying figures, each of the force application motors 3a and 3b comprises a force application device of its own, constituting a mechanical emergency route for this motor.

For simplicity, only a first force application device will be described and illustrated in Figures 4 to 8, the second device being identical.

In Figure 1, the alphanumeric references ending with the letter "a" correspond to the X axis of roll. References ending with the letter "b" are the same, transposed to the Y pitch axis.

Figure 2 shows a structural embodiment of the lever 1 mounted on the mechanical seal 10. The seal 10 is mounted on the frame 2 which is secured to a frame of the aircraft. The force application motors 3a and 3b (not visible) are here offset from the lever.

Lever 1 is free at one end and attached to a first plate 101 at the other end. The first plate 101 is movable in rotation along the X axis and along the Y axis and is linked to a second plate 102 of the seal 2. The X axis is linked to the first plate 101, so that a pivoting of the first plate 101 around the Y axis rotates the X axis around the Y axis.

Two transmissions, each comprising a Cardan joint, translate a rotational movement of the lever along the X axis, respectively along the Y axis, into a rotational movement of the associated drive shaft (not shown) extending along axis A, respectively along axis B.

The drive shafts of the motors are thus mechanically linked to the lever. The motors 3a and 3b are in direct engagement with the mechanical seal 10 and can transmit a resistive or motor force in response to the pivoting movements of the lever 1 by the pilot, according to a force law or a predetermined damping law.

Figure 3 shows the steering lever and the force application device in side view. Lever 1 is here in a neutral position. Usually, the neutral position corresponds to a position where the piloting controls act neither in roll nor in pitch on the moving parts of the aircraft. The lever 1 is mounted on the cockpit cabin at the level of a base having a bellows 17. The engines 3a and 3b are therefore hidden by the walls of the cockpit of the aircraft.

The roll motor 3a and the pitch motor 3b are, in this example, of identical dimensions. The elements providing the mechanical emergency route for the motors are here located under the motors, inside the box 50. The drive shafts associated with the motors extend inside the box 50. The latter is fixed relative to the housing. housing 4.

For more details on the structure of the mechanical seal 10 and on the mechanical connection with the motors 3a and 3b, reference may be made to FIG. 1 of document FR 3 011 815 and to the description relating thereto.

Stress application device

The piloting system comprises a mechanical emergency channel for at least one of the force feedback motors 3a and 3b (and, preferably, for each of these motors), in order to prevent the rotation of the lever 1 from occurring. is completely free in the event of an electrical failure affecting said motor. In what follows, the mechanical emergency channel for the roll motor 3a driving the shaft 41a of axis A. ".

The emergency path is produced by the force application device which comprises a first pin 30a, a second pin 40a, means 7a for tightening the first pin and the second pin, an electromagnet 5a, an actuator 6a comprising a magnetic material and a housing 4. The housing is so lidar of an aircraft frame. The stress application device has two distinct configurations:

- an operating configuration, in which the actuator 6a is in a position bearing the reference 6-2 in the figures, in which the electromagnet 5a is active and requests the actuator 6a,

- a blocking configuration, in which the electromagnet is inactive and in which the actuator 6a is in a position bearing the reference 6-1 in the figures. The first pin 30a then undergoes a resistive force opposing rotational movements of the first pin 30a relative to the housing 4 about the axis A, a first tooth 71 and a second tooth 74 of the clamping means 7a clamping together the first pawn 30a and second pawn 40a.

In particular, in the example below, the second pin 40a is carried by an output mesh facing an input mesh linked to the housing.

Thus, the fact of supplying current to the electromagnet 5a, or of cutting the current, causes a displacement of the actuator 6a and a change of configuration of the force application device. In the example below, in the operating configuration, the input and output meshes are not engaged.

Conversely, when the force application device is in the lockout configuration, both meshes are engaged. The housing 4 being fixed relative to the frame 2 and the first pin 30a being connected to the drive shaft 41a of the motor 3a, the pilot feels a resistive force when he tries to move the lever 1 in the direction of roll. - despite the failure of the electric roll motor 3a.

According to an advantageous embodiment, the force application device comprises a disengagement device 16a allowing disengagement of the two meshes 62 and 63, even when the standard supply circuit of the electromagnet 5a is faulty. The release device 16a comprises a second power supply circuit for re-energizing, on command, the electromagnet 5a and reactivating the latter. The second electromagnet supply circuit is separate from its standard supply circuit. Advantageously, the release device 16a comprises a user interface located on the lever 1, such as a button type switch. For example, while the pilot presses the button, the electromagnet is active again and the input and output meshes are disengaged. The pilot is able to reposition the lever along the roll and pitch axes, without being subjected to resistive stress from the force application device, while the button is pressed. The first pawn 30a and the second pawn 40a are repositioned at the same time as the lever.

If the standard supply circuit of the electromagnet 5a is the same as the supply circuit of the motor 3a, such a release device provides the possibility for the pilot to disengage the input and output meshes even during the process. power supply failure of motor 3a in order to reposition the "neutral point" of lever 1 as required.

The pilot can thus select the neutral point serving as a reference for the force law exerted by the force application device in the locking configuration.

CLAIMS

1. Device for applying force for a pilot stick of an aircraft, in which the pilot stick comprises a control lever (1) connected to at least one motor (3a) comprising a drive shaft, the 'drive shaft being movable in rotation about an axis (A), the force application device comprising:

a first pawn (30a), connected to the tree,

a housing (4), configured to be fixed relative to the aircraft, - an electromagnet (5a),

an actuator (6a) movable relative to the housing, said actuator comprising a magnetic material,

a coupling device comprising an input mesh (63), connected to the housing, and an output mesh (62) configured to cooperate with the input mesh,

said output engagement comprising a second pin (40a), clamping means (7a) of the first pin and of the second pin, said clamping means comprising a first tooth (71) and a second tooth (74) configured to clamp the first pin and the second pin, the force application device having an operating configuration, in which the electromagnet (5a) is active and the output mesh is positioned away from the input mesh of so that the second pin (40a) is movable in rotation around the axis (A), and a locking configuration, in which the electromagnet (5a) is inactive and the output mesh is engaged with the input meshing so as to block the second pin (40a) from rotating relative to the housing (4).

2. A force application device according to claim 1, the actuator (6a) being mounted on the input mesh (63).

3. Force application device according to claim 2, the electromagnet (5a) being mounted on the housing (4), so that the actuator (6a) is in an axial position between the electromagnet. magnet (5a) and the output mesh (62) along the axis (A).

4. Force application device according to one of claims 1 to 3, comprising return means (64) comprising a first end fixed to the housing (4) and a second end fixed to the input mesh ( 63), the return means being configured to move the input mesh along the axis (A).

5. A force application device according to one of claims 1 to 4, wherein one of the input mesh (63) and the output mesh (62) comprises at least one tooth (65 ), the other among the input mesh (63) and the output mesh comprising at least one complementary housing (66), the tooth being configured to enter the complementary housing in the locking configuration.

6. A force application device according to one of claims 1 to 5, wherein the clamping means comprise a first jaw (70) and a second jaw (73), the device further comprising an elastic connection in compression. , such as a compression spring, connecting the first jaw and the second jaw so as to urge the first tooth (71) and the second tooth (74) against the first pin (30a) and the second pin (40a) in configuration Operating.

7. A force application device according to one of claims 1 to 6, further comprising an angular displacement sensor (11 a) configured to acquire a measurement of angular displacement of the shaft.

8. A force application device according to one of claims 1 to 7, further comprising a damping part (14a) extending on a contact surface (31) between the first pin (30a) and the second pawn (40a).

9. A force application device according to one of claims 1 to 8, further comprising a disengaging device (16a) configured to disengage the input mesh (62) and the output mesh (63). , said device (16a) comprising a second power supply circuit distinct from a standard power supply circuit of the electromagnet (5a), in order to allow disengagement of said meshes while the standard power supply circuit of the electromagnet is faulty.

10. Cockpit of an aircraft comprising a control lever

(1), comprising at least one motor (3a) which has a drive shaft, the drive shaft being movable in rotation about an axis (A), the handle further comprising a device for applying d 'force according to one of claims 1 to 9 per motor.