METHOD FOR DETERMINING THE POSITION OF AN ACTUATING DEVICE, CORRESPODNING ACTUATING DEVICE

Abstract

A method determines the position of an actuating device of an element of an aircraft seat. The actuating device includes a calculating unit, an actuator movably mounted on an output shaft for actuating the element, the output shaft being connected to an angular position encoder so a position (X) of the actuator on the output shaft corresponds to a single angular position () of the encoder. The method includes a preliminary submethod of automatically calibrating the actuating device including: placing the actuator at a predetermined position (Xref) corresponding to an expected angle value (att) of the encoder; measuring an initial positioning angle value (ini) of the encoder when the actuator shaft is in the predetermined position (Xref); comparing the initial positioning angle value (ini) and the expected angle value (att) calculating the angular offset of the encoder signal, with dcal=(iniatt) [MODULO 360], decal being between 0 and 359.

Claims

1. Method for determining the position of an actuating device of at least one element for actuating an aircraft seat, the actuating device comprising a calculating unit, an actuator mounted to be movable in translation and/or in rotation on an output shaft so as to actuate the corresponding at least one element of an aircraft seat, said output shaft being connected to an angular position encoder so that a position (X) of the actuator on said output shaft corresponds to a single angular position () of the angular position encoder, the method comprising a preliminary submethod of automatically calibrating said actuating device comprising the following steps: a step of placing the actuator at a predetermined position (Xref) corresponding to an expected angle value (att) of the encoder; a step of measuring an initial positioning angle value (ini) of the angular position encoder when the actuator shaft is in the predetermined position (Xref); a step (103) of comparing said initial positioning angle value (ini) and said expected angle value (att); a step (104) of calculating the angular offset (decal) of the angular position encoder signal, with dcal=(iniatt) [MODULO 360], decal being between 0 and 359.

2. Method for determining the position of an actuating device according to claim 1, further comprising a step of measuring the position (X(t)) of the actuator at a given moment according to the following relationship: $X\left(t\right)=\frac{\left[\left(+\mathrm{dcal}\right)\left[\mathrm{MODULO}360\right]\right]}{K}+X\min$ with Xmin a minimum position of the actuator, with K a proportion coefficient between the angle value sent by the encoder and the value of the actuator position.

3. Method for determining the position of an actuating device according to claim 2, further comprising a step of determining a position of at least one element to be actuated of an aircraft seat as a function of said position of the actuator at a given moment X(t).

4. Method for determining the position of an actuating device according to claim 1, further comprising a step of determining a minimum angular position (min) of the encoder corresponding to a minimum position (Xmin) of said actuator, and a maximum angular position (max) of the encoder corresponding to a maximum position (Xmax) of said actuator, the maximum angular position (max) and the minimum angular position (min) having an absolute variance of less than 360 degrees.

5. Method for determining the position of an actuating device according to claim 4, wherein if (min)>(max), the method comprises, for 355<<365: a step of detecting the direction of rotation of said angular encoder; a step of deactivating said step of measuring the position (X(t)) of the actuator at a given moment for a predetermined period.

6. Actuating device of at least one element for actuating an aircraft seat, the actuating device comprising a calculating unit, an actuator provided with an output shaft so as the actuate the corresponding at least one element of an aircraft seat, said output shaft being connected to an angular position encoder so that a position (X) of the actuator on said output shaft corresponds to a single angular position () of the encoder, said device being configured to implement a method for determining the position of the actuating device according to claim 1.

7. Actuating device according to claim 6, wherein the actuator can be moved between a minimum position (Xmin) corresponding to a single minimum angular position (min) of the encoder and a maximum position (Xmax) corresponding to a single maximum angular position (max) of the encoder, the deviation between the maximum angular position (max) and the minimum angular position (min) being less than 360 degrees.

8. Actuating device according to claim 7, wherein the deviation between the minimum position (Xmin) of the actuator and the maximum position (Xmax) of the actuator is between 100 mm and 800 mm, preferably between 500 mm and 700 mm, still more preferably equal to 600 mm.

9. Actuating device according to claim 6, wherein the encoder is a magnetic encoder having a periodical proportional increasing or decreasing ramp response, the angular position () at a given moment being measured by measuring the magnetic axis of a radially magnetised magnet attached to the actuator.

10. Actuating device according to claim 6, wherein said calculating unit comprises a hysteresis filter.

11. Aircraft seat, comprising at least one element of a movable seat mobile, wherein the seat is provided with at least one actuating device according to claim 6.

Description

PRESENTATION OF THE FIGURES

[0038] The invention, and its various advantages, will be better understood in the light of the following description of an illustrative and non-limiting embodiment thereof, and the accompanying drawings, in which:

[0039] FIG. 1 is a diagram illustrating an aircraft seat according to one embodiment of the invention;

[0040] FIG. 2 is a diagram illustrating an actuating device of at least one element to be actuated of an aircraft seat according to the embodiment of FIG. 1, and

[0041] FIG. 3 is a diagram illustrating a method for determining the position of an actuating device of at least one element to be actuated of an aircraft seat according to any embodiment of the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

[0042] The principle of the invention is based on the implementation of a method for determining the position of an actuating device 1 of at least one element 2 to be actuated of an aircraft seat 10, this method comprising a preliminary submethod 100 for automatically calibrating the actuating device 1 so as to limit the constraints applied to the system without requiring the implementation of additional part to operate, while being relatively simple mechanically and not very time-consuming to carry out for each of the actuators.

[0043] A first embodiment of a method for determining the position of an actuating device of at least one element to be actuated of an aircraft seat, an actuating device of at least one aircraft seat element to be actuated, and an aircraft seat is now presented in relation to FIGS. 1 to 3.

[0044] FIG. 1 shows an aircraft seat comprising three elements to be actuated 2 in the form of seat elements. Here, these seat elements 2 correspond to a reclining backrest, a seat and a leg rest.

[0045] These elements 2 of the aircraft seat 10 are capable of being moved by means of an actuating device 1 including actuators 3. This movement of elements 2 of the aircraft seat 10 allows modification of the configuration of use of the aircraft seat 10.

[0046] The configuration of use of the aircraft seat 10 comprises, for example, a TTL (taxiing, take-off and landing) position, or a sleeping position, also known as a the bed position. The configuration of use of the aircraft seat 10 can also further comprise a reference or default position.

[0047] The actuators 3 can be electric actuators for example. Alternatively, the actuators are hydraulic actuators, pneumatic actuators, or any other known type of actuator.

[0048] Each of the actuators 3 is mounted to be movable in and/or in rotation on an output shaft so as to actuate the corresponding element(s) 2 of the aircraft seat 10.

[0049] As illustrated in FIG. 2, in this embodiment, the actuators 3 are moved in translation and/or in rotation by means of one or more motors 31.

[0050] This output shaft 30 is connected to an angular position encoder 9. This encoder is, in this embodiment, a magnetic encoder with a periodically increasing or decreasing proportional ramp response. With this magnetic encoder, the angular position at a given moment is measured by measuring the magnetic axis of a radially magnetised magnet fixed to the actuator 3.

[0051] Here, this output shaft 30 is connected to the angular position encoder 9 such that a position X of the actuator on the output shaft 30 corresponds to a single angular position of the angular position encoder 9.

[0052] More particularly, the movement of the output shaft 30 is transmitted to the encoder 9, for example via a mechanical linkage 32 including a reduction as illustrated in FIG. 2, so that a translation and/or rotation of the actuator 3 on the shaft 30 results in a rotation of the encoder 9.

[0053] Here, the actuator 3 can be moved between a minimum position Xmin corresponding to a single minimum angular position min of the encoder 9 and a maximum position Xmax corresponding to a single maximum angular position max of the encoder 9.

[0054] So that a position X of the actuator on the output shaft 30 corresponds to a single angular position of the encoder 9, the deviation between the maximum angular position max and the minimum angular position min is less than 360 degrees, i.e. one period.

[0055] According to the embodiments, the deviation between the minimum position Xmin of the actuator 3 and the maximum position Xmax of the actuator 3 is between 100 mm and 800 mm.

[0056] Preferably, the deviation between the minimum position Xmin of the actuator 3 and the maximum position Xmax of the actuator 3 is between 500 mm and 700 mm.

[0057] In this embodiment, the deviation between the minimum position Xmin of the actuator 3 and the maximum position Xmax of the actuator 3 is equal to 600 mm.

[0058] In order to know the positioning of the actuators, a calculating unit 4 is used and is connected to each of these actuators 3.

[0059] This calculating unit 4 is firstly provided with means 40 for obtaining the angular position of the encoder 9. It also comprises means 41 for converting the angular position into the relative position X(t) of the shaft 3. It further comprises means 42 for outputting the relative position X(t) of the shaft 3.

[0060] This calculating unit 4 can also comprise a hysteresis filter.

[0061] Due to the random positioning of the encoder 9 with respect to the output shaft 30, it is necessary, prior to the use of the seat, to calibrate the various actuators so that the actuating device is capable of controlling the movement of each actuator.

[0062] Accordingly, the method for determining the position of an actuating device 1 comprises a preliminary submethod 100 of automatically calibrating the actuating device 1 comprising the following steps: [0063] a step 101 of placing the actuator at a predetermined position Xref corresponding to an expected angle value att of the encoder; [0064] a step 102 of measuring an initial positioning angle value ini of the angular position encoder 9 when the shaft of the actuator is in the predetermined position Xref; [0065] a step 103 of comparing said initial positioning angle value ini and said expected angle value att, and [0066] a step 104 of calculating the angular offset decal of the angular position encoder signal, with dcal=(iniatt) [MODULO 360], decal being between 0 and 359.

[0067] In other words, a value att is attributed which is to be attributed in the actuator movement control for an actuator shaft reference position 30 on the aircraft seat movement.

[0068] For this predetermined reference position Xref of the actuator shaft 30 assigned an expected angle value att, the encoder 9 returns an initial positioning angle ini, within the 360 measurement period, from which the modulation by the MODULO 360 function.

[0069] The initial positioning angle value ini, i.e. the measured angle, can then be compared with the expected angle value att, and the offset decal can be deduced by the relationship:

dcal=(iniatt)[MODULO 360]

[0070] This calibration step, or angular setting, step, makes it possible to determine and remember the angular offset of one encoder to another between its measured angular value and the angular value expected for the position of the shaft installed in the course of the movement to be controlled. As this offset is permanent, its identification and storage in the calibration phase allows a permanent measurement correction in the operating phase.

[0071] According to a preferred embodiment of the invention, it may be provided that the device comprises a memory for saving this angular offset value decal.

[0072] Following a first calibration, which may be repeated if necessary, the method of determining the position of the actuating device 1 may enter a normal operating mode, or operating mode and comprises a step 105 of measuring the position X(t) of the actuator 3 at a given movement according to the following relationship:

[00002]$X\left(t\right)=\frac{\left[\left(+\mathrm{dcal}\right)\left[\mathrm{MODULO}360\right]\right]}{K}+X\min$

with Xmin being the minimum position of the actuator, and with K being a proportion coefficient between the angle value sent by the encoder and the value of the actuator position.

[0073] It should be noted that this coefficient K can be given for example by manufacturers of the encoder or the actuator.

[0074] Then, after measuring the position X(t) of the actuator, the determination method comprises a step 106 of determining a position of at least one element 2 to be activated of the aircraft seat 10 as a function of the position of the actuator at a given moment X(t).

[0075] According to one variant of the invention, the method can also comprise a step of determining a minimum angular position min of the encoder 9 corresponding to a minimum position Xmin of the actuator 3, and a maximum angular position max of the encoder 9 corresponding to a maximum position Xmax of the actuator 3.

[0076] As already discussed, the maximum angular position max and the minimum angular position min have an absolute deviation of less than 360 degrees.

[0077] Due to the random positioning of the encoder 9 with respect to the output shaft 30, and the maximum 360 period of use of the encoder 9, an output signal transition due to the encoder passing from the end of the period of one revolution and the beginning of a second revolution may occur once, anywhere in the angular operating range of the encoder. Accordingly, in this embodiment if (min)>(max), the method comprises, for 355<<365: [0078] a step of detecting the direction of rotation of the angular encoder 9, and [0079] a step of deactivating step 105 of measuring the position X(t) of the actuator at a given moment for a predetermined duration.

[0080] These two steps make is possible, on the one hand, to detect the direction of rotation of the angular encoder and therefore to know whether the angular encoder is approaching or moving away from a value indicating the proximity of the signal transition, and, on the other hand, to take no measurements for a predetermined period of time, this predetermined period of time making it possible to pass the angular position corresponding to the signal transition and thus not to falsify the measurements.

[0081] According to the illustrated embodiment, this step is performed if min>max and if for 355<<365. However, according to variants, the range of values can be adjusted in particular to the desired sensitivity for setting the seat elements in motion.

[0082] Furthermore, the predetermined duration can be for example between 10 and 20 ms. According to the illustrated embodiment, the predetermined period is equal to 15 ms.