Force application device for an active mini-stick and mechanical backup control method

Patent metadata

Field	Value
Publication number	US-2022057826-A1
Application number	US-201917275386-A
Country	US
Kind code	A1
Filing date	Sep 13, 2019
Priority date	Sep 13, 2018
Publication date	Feb 24, 2022
Grant date	—

Abstract

A force application device for an aircraft control stick in provided. The device includes a mechanical joint, a force motor, a rheological brake, and a control device. The mechanical joint receives a lever of an aircraft pilot stick and is rotatably movable. The force motor includes a motor shaft extending along a third axis, the rotation of the motor shaft being linked to the rotation of the mechanical joint. The force motor exerts a resistive torque on the motor shaft. The rheological brake includes two facing parts, and has a volume delimited by the two facing parts, the volume being adapted to contain a rheological material. One of the parts is arranged on the motor shaft and rotatably movable about the third axis relative to the other of the parts. The control device applies an electromagnetic field within the volume so as to vary shear strength of the rheological material.

First claim

1 - 19 . (canceled)

20 . A force application device for an aircraft pilot stick, the device comprising:
a mechanical joint configured to receive a lever of an aircraft pilot stick, the mechanical joint being rotatably movable about a roll axis and about a pitch axis, a force motor comprising a motor shaft extending along a third axis, the rotation of the motor shaft about the third axis being linked to the rotation of the mechanical joint about an axis taken among the roll axis or the pitch axis, the force motor being configured to exert a resistive torque on the motor shaft, a rheological brake comprising two facing parts facing each other, the brake comprising a volume delimited by said two facing parts, the volume being adapted to contain a rheological material, one of said two parts being arranged on the motor shaft and being rotatably movable about the third axis relative to the other of said two facing parts, and a control device controlled to apply an electromagnetic field within said volume so as to vary shear strength of the rheological material.

21 . The force application device according to claim 20 , wherein the rheological material is a magnetorheological fluid comprising suspended magnetic particles, or wherein the rheological material is an electrorheological fluid comprising suspended conductive particles, the control device being controlled to apply a variable magnetic or electric field.

22 . The force application device according to claim 20 , wherein the rheological material is a magnetic powder dispersed between the two facing parts.

23 . The force application device according to claim 20 , wherein the force motor is a torque motor.

24 . The force application device according to claim 20 , wherein the force motor is a direct drive motor.

25 . The force application device according to claim 20 , wherein the rheological brake is positioned on the motor shaft opposite the mechanical joint relative to the force motor.

26 . The force application device according to claim 20 , wherein the rheological brake is positioned on the motor shaft between the mechanical joint and the force motor.

27 . The force application device according to claim 20 , the force application device comprising a motor shaft rotational speed sensor, the rheological brake being piloted according to a speed servo-control as a function of a rotational speed acquired by said sensor.

28 . The force application device according to claim 20 , wherein the two facing parts of the rheological brake are a first disk extending radially from the motor shaft and a second disk facing the first disk, the first disk and the second disk being centered on the third axis.

29 . The force application device according to claim 20 , wherein the two facing parts of the rheological brake are: a sphere centered on the third axis and at least partially immersed in the rheological material, and a spherical base.

30 . The force application device according to claim 20 , wherein the control device is controlled to apply an electromagnetic field increasing the shear strength of the rheological material, the event of fault on a processing chain of the force motor.

31 . The force application device according to claim 30 , wherein the slip torque of the rheological material is comprised between 10 N·m and 100 N·m, preferably between 10 N·m and 75 N·m.

32 . The force application device according to claim 27 , further comprising a roll force sensor configured to measure a roll torque exerted on the lever and/or a pitch force sensor configured to measure a pitch torque exerted on the lever, to allow a force-piloting of the pilot stick.

33 . The force application device according to claim 20 , wherein the rheological brake is configured to exert a resistive torque on the mechanical joint, a value of which is limited to 70 Nm, preferably 25 Nm, as a function of an electric current provided to the control device.

34 . The force application device according to claim 20 , wherein the control device is controlled according to a predetermined law to exert an electromagnetic field which is a function of a position and/or speed of the lever.

35 . The force application device according to claim 20 , wherein the force motor is a roll motor, the rotation of the motor shaft being linked to the rotation of the mechanical joint about the roll axis, the rheological brake being adapted to exert a force feedback on the roll axis the device further comprising a pitch motor comprising a pitch motor shaft extending along a fourth axis, the rotation of the pitch motor shaft being linked to the rotation of the mechanical joint about the pitch axis, and
the force application device comprises an additional rheological brake adapted to exert a force feedback on the pitch axis.

36 . An active aircraft pilot stick comprising:
the force application device according to claim 20 , and a lever able to rotate about the roll axis and the pitch axis the lever being arranged on the mechanical joint.

37 . A method for mechanical back-up monitoring of a device for applying a force on an aircraft pilot stick, the method being implemented using the force application device according to claim 20 and comprising the steps of:
detecting a fault on a processing chain of a force motor of the force application device, and
generating an electromagnetic field control below a slip torque of a rheological material contained in a rheological brake of the force application device, said control being transmitted to a device for controlling the force application device to block the lever.

38 . The method according to claim 37 , further comprising:
activating a force pilot mode of the pilot stick.

39 . A method for damping control of a device for applying a force on an aircraft pilot stick, the method being implemented using the force application device according to claim 20 , the method comprising the steps of:
detecting a position and/or speed of a lever in rotation about a roll axis or a pitch axis, the lever being arranged on a mechanical joint of the force application device, generating an electromagnetic field control according to a predetermined law as a function of the detected position and/or speed, said control being transmitted to a device for controlling the force application device, so that a rheological brake of the force application device exerts a resistive torque opposing a rotational movement of the lever as a complement to a force motor of the force application device.

Assignees

• Safran Electronics & Defense

Inventors

• Lawniczak Rémi-Louis
• Coppee Pascal
• Baro Nicolas
• Attrazic Yannick Ghislain

Classifications

• G05G2009/04766

  providing feel, e.g. indexing means, means to create counterforce · CPC title

• G05G9/047 Primary

  the controlling member being movable by hand about orthogonal axes, e.g. joysticks {(for switches H01H25/04)} · CPC title

• G05G2009/04718

  with cardan or gimbal type joint · CPC title

• H02K26/00

  Machines adapted to function as torque motors, i.e. to exert a torque when stalled · CPC title

• H02K11/24

  Devices for sensing torque, or actuated thereby (H02K11/27 takes precedence) · CPC title