The invention relates to piloting devices used by the pilot in an aircraft cockpit, in particular 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 lever mounted to rotate about a so-called roll axis and a so-called pitch axis, these two axes being orthogonal to each other. 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 and there is no direct mechanical feedback to the lever.

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".

As such, it has been proposed 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 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 piloting mode without force feedback in the event of a failure.

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. In addition, the introduction of gears implies a reduction in the dynamic performance of the stick, which increases inertia, and causes a loss of ergonomics because the pilot feels the variations in torque due to the gears.

SUMMARY OF THE INVENTION

There is thus a need for a mini piloting stick incorporating a mechanical emergency channel, to prevent the rotation of the lever from being completely free in the event of an electrical failure affecting a force feedback motor.

The desired sidestick must not be able to switch, in the event of a failure, into a mode in which the pilot can freely pivot the lever without feeling a resistive force.

There is a subsidiary need for a mini-stick of less mass, size and power consumption.

In general, the reliability, simplicity and ergonomics of the force feedback devices for the sidestick can be improved.

For this, the invention provides 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 around an axis. The stress application device includes:

- a casing, configured to be fixed relative to the aircraft

- an electromagnet, mounted on the housing,

- an actuator, mounted on the shaft, said actuator being movable in translation relative to the shaft along the axis, the actuator comprising a magnetic material and

- a coupling device comprising an input meshing mounted fixed relative to the housing and an output meshing connected to the actuator via a fastening part, said fastening part being nt configured to allow limited angular travel between the output mesh and the shaft around the axis and to allow translation of the output mesh actuator along the axis.

Some preferred but non-limiting features of the device described above are as follows, taken individually or in combination

- The fastener comprises a spring having torsional stiffness and axial stiffness, the torsional stiffness being greater than the axial stiffness, preferably at least three times greater.

- the fixing part comprises a flexible plate.

- the fixing part is preloaded and applies a force on the actuator and on the output meshing, so that when the electromagnet is not supplied, the fixing part exerts a return force on the actuator and on the output mesh towards the input mesh.

- the fastening part further comprises a ring comprising engagement means, the shaft comprising engagement means of corresponding shape and dimension so that their mutual engagement makes it possible to secure the ring and the shaft in rotation around of the axis.

- the spring comprises a first portion attached to the ring and a second portion attached to the output gear.

- one of the input meshing and the output meshing comprises at least one tooth, the other comprising at least one complementary housing, the tooth being configured to enter the housing to block the output meshing in rotation relative to the input mesh when the actuator moves the output mesh to the input mesh.

- The input gear is fixedly mounted on an input of a torque limiter, an output of said torque limiter being fixedly mounted on the housing.

- The device comprises two motors each comprising a drive shaft movable in rotation about an associated axis, an electromagnet, an actuator, a housing, a coupling device and a fixing part being associated with each shaft.

the device further comprises a first and a second force sensor, fixed to the lever, and a control unit configured to determine control signals for moving parts of the aircraft as a function of the forces measured by the first and the second force sensor.

According to a second aspect, the invention provides a control stick of an aircraft comprising a control lever connected to at least one engine

comprising a drive shaft rotatable about an axis and a force application device as described above.

Optionally, the piloting stick further comprises at least one force sensor, mounted on the lever or on a single piece of the lever so as to detect a force applied to the lever by a pilot, and transmission means of a force supplied by the force sensor to a control unit configured to determine control signals for moving parts of the aircraft as a function of the forces measured by the first and the second force sensor.

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, and with regard to the appended drawings given by way of non-limiting examples and in which:

Figure 1 schematically shows a pilot stick architecture according to one embodiment of the invention.

Figure 2 is a perspective view of a lever and a mechanical seal of an exemplary embodiment of a mini-handle.

Figure 3 is a sectional view of an exemplary embodiment of a force application device according to one embodiment of the invention.

Figure 4 is an exploded view of the embodiment of Figure 3.

DETAILED DESCRIPTION OF AN EMBODIMENT

Overall architecture of the control system

There is shown in Figure 1 a functional architecture of the piloting system of an aircraft along its roll and pitch axes including in particular a mini-control stick. The sidestick is typically found in the cockpit of the aircraft.

In this figure, the thicker lines between two functional units correspond to mechanical links. The other arrow links are electronic links through which data can flow.

The system comprises a control lever 1 rotatably mounted on a plate of a mechanical seal 2 along a roll X axis and a lever pitch Y axis, the two axes being orthogonal. The mechanical seal 2 is fixed to a frame integral with the floor of the cockpit of the aircraft.

Position sensors, preferably a sensor 4a associated with the roll axis and a sensor 4b associated with the pitch axis, communicate electronic signals of the rotary position of the lever 1 respectively along the X and Y axes to a computer 7 .The computer 7 controls the force application device to achieve a predetermined force law. The computer 7 comprises an electronic interface for receiving said position signals. Optionally, the sensors 4a and 4b also communicate information on the speed of rotation of the lever 1 along these axes. The position / speed information of the lever is translated into control signals for piloting moving parts of the aircraft by a flight control unit 8, or FCS for "Flight Control System".

As will be described below, the control unit 8 is also configured to determine, based on the position / speed information of the lever and possibly other information, commands to apply force to the lever 1. The computer 7 determines, based on the force application commands, control signals from the force application device associated with the sidestick.

In the present example, the force application device comprises an electric motor 3a associated with a shaft 13 of axis A 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 device comprises an electric motor 3b associated with a shaft of axis B linked to the pitch Y axis of the lever.

CLAIMS

1. Device (20) 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, 3b) comprising a shaft (13) drive movable in rotation about an axis (A), the force application device comprising:

- a housing (24), configured to be fixed relative to the aircraft, an electromagnet (22), mounted on the housing (24), - an actuator (30), mounted on the shaft (13), said actuator ( 30) being movable in translation relative to the shaft (13) along the axis (A), the actuator (30) comprising a magnetic material and

- a coupling device comprising an input engagement (40) mounted fixed relative to the housing (24) and an output engagement (50) connected to the actuator (30) by means of a fastening part (60), said fastener (60) being configured so as to allow a limited angular movement between the output meshing (50) and the shaft (13) around the axis (A) and to allow translation of the actuator (30) of the output mesh (50) along the axis (A).

2. Device (20) according to claim 1, wherein the fixing part (60) comprises a spring (62, 64) having a torsional stiffness and an axial stiffness, the torsional stiffness being greater than the axial stiffness, of preferably at least three times larger.

3. Device (20) according to claim 2, wherein the fixing part (60) comprises a flexible plate.

4. Device (20) according to one of claims 2 or 3, wherein the fixing part (60) is prestressed and applies a force to the actuator

(30) and on the output meshing (40), so that when the electromagnet (22) is not supplied, the fixing part (60) exerts a return force on the actuator (30) and on the output mesh (50) towards the input mesh (40).

5. Device (20) according to one of claims 2 to 4, wherein the fixing part (60) further comprises a ring (68) comprising engagement means (69), the shaft (13) comprising engagement means of corresponding shape and dimension so that their mutual engagement enables the ring (68) and the shaft (13) to be secured in rotation around the axis (A).

6. Device (20) according to claim 5, wherein the spring (62, 64) comprises a first portion (62) fixed to the ring (68) and a second portion (64) fixed to the output mesh (50). ).

7. Device (20) according to one of claims 1 to 6, wherein one of the input mesh (40) and the output mesh (50) comprises at least one tooth (54), the 'another comprising at least one complementary housing (42), the tooth (54) being configured to enter the housing (42) to block the output mesh (50) in rotation with respect to the input mesh (40 ) when the actuator (30) moves the output mesh (50) to the input mesh (40).

8. Device (20) according to one of claims 1 to 7, wherein the input mesh (40) is fixedly mounted on an input (27) of a torque limiter (26), an output (29 ) of said torque limiter (26) being fixedly mounted on the housing (24).

9. Device (20) according to one of claims 1 to 8, comprising two motors (3a, 3b) each comprising a drive shaft (13) movable in rotation about an axis (A) associated, an electromagnet ( 22), an actuator (30), a housing (24), a coupling device and a fastener (60) being associated with each shaft (13).

10. Device (20) according to one of claims 1 to 9, further comprising a first and a second force sensor (6a, 6b), fixed on the lever (1), and a control unit (8) configured to determine control signals for moving parts of the aircraft as a function of the forces measured by the first and second force sensors.

11. Pilot handle of an aircraft comprising a control lever (1) connected to at least one motor (3a, 3b) comprising a drive shaft (13) movable in rotation about an axis (A) and a force application device (20) according to one of claims 1 to 10.

12. Steering stick according to claim 11, further comprising at least one force sensor (6a, 6b), mounted on the lever (1) or on a single piece of the lever (1) so as to detect an applied force. on the lever (1) by a pilot, and means for transmitting a force supplied by the force sensor to a control unit (8) configured to determine control signals for moving parts of the aircraft as a function of forces measured by the first and second force sensors.