FR2895083A1

FR2895083A1 - DEVICE FOR AUTOMATIC POSITIONING OF A HELMET

Info

Publication number: FR2895083A1
Application number: FR0553897A
Authority: FR
Inventors: De Tapol Marc Vincens
Original assignee: TDM SOC PAR ACTIONS SIMPLIFIEE
Current assignee: TDM SOC PAR ACTIONS SIMPLIFIEE
Priority date: 2005-12-15
Filing date: 2005-12-15
Publication date: 2007-06-22
Anticipated expiration: 2025-12-15
Also published as: WO2007068860A3; WO2007068860A2; FR2895083B1

Abstract

L'objet de l'invention est un dispositif de positionnement automatique selon au moins un axe de rotation d'un élément susceptible d'évoluer dans un milieu sensiblement aux perturbations notamment électromagnétiques, tel qu'un casque d'aéronef par exemple, ledit dispositif comprenant au moins un mât (16) à l'extrémité duquel est articulé selon un axe de rotation un support (24, 36) auquel peut être assujetti ledit élément, caractérisé en ce qu'il comprend au moins une motorisation (28, 44) déportée par rapport audit axe de rotation, susceptible d'entraîner ledit axe de rotation par le biais d'une chaîne cinématique ainsi qu'au moins un codeur (52,54) susceptible de contrôler le mouvement réel dudit axe de rotation afin de compenser notamment les éventuels jeux de la chaîne cinématique.The object of the invention is an automatic positioning device according to at least one axis of rotation of an element capable of evolving in a medium substantially to disturbances, particularly electromagnetic disturbances, such as an aircraft helmet for example, said device comprising at least one mast (16) at the end of which is articulated along an axis of rotation a support (24, 36) to which said element may be secured, characterized in that it comprises at least one motor (28, 44) offset relative to said axis of rotation, capable of driving said axis of rotation by means of a kinematic chain and at least one encoder (52,54) capable of controlling the real movement of said axis of rotation to compensate in particular the possible games of the kinematic chain.

Description

bISPOSITIF bE POSITIONNEMENT AUTOMATIQUE b'UN CASQUEbISPOSITIVE bE AUTOMATIC POSITIONING b'UN HELMET

La presente invention se rapporte a un dispositif de positionnement automatique d'un casque, plus particulierement selon I'axe de site et/ou de roulis. Pour caracteriser un casque, notamment un casque de pilote d'aeronef, it est necessaire de positionner ce dernier selon des milliers de positions differentes, a la maniere d'un pilote qui bougerait sa tete, af in de verifier notamment si I'affichage sur la visiere suit bien en temps reel ('evolution du champ de vision du pilote. Une solution pour realiser cette operation consiste a positionner manuellement le casque selon ces differentes positions. Cette tache est longue et fastidieuse. The present invention relates to a device for automatic positioning of a helmet, more particularly according to the axis of site and / or roll. To characterize a helmet, especially an aircraft pilot helmet, it is necessary to position the helmet in thousands of different positions, in the manner of a pilot who would move his head, to check in particular if the display on the visor follows in real time ('evolution of the field of vision of the pilot.) A solution to perform this operation is to manually position the helmet in these different positions.This task is long and tedious.

Pour accelerer cette operation, un banc a ete developpe comprenant un support motorise permettant d'assurer trois translations Tx, Ty, Tz et une rotation verticale Rz. Les deux autres rotations horizontales Rx correspondant au mouvement avant/arriere de la tate appele egalement site et Ry correspondant au mouvement droite/gauche de la tate appele egalement roulis ne sont pas motorisees car I'environnement proche du casque a tester est un milieu sensible aux perturbations electromagnetiques si bien que la presence d'une motorisation pour automatiser les mouvements de rotation Rx et Ry est proscrite. Par consequent, I' operation de caracterisation d'un casque est relativement longue et fastidieuse car le positionnement necessitant un changement selon les axes de rotation Rx et Ry est realise manuellement. Aussi, la presente invention vise a pallier les inconvenients des dispositifs de fart anterieur en proposant un dispositif permettant un positionnement automatique du casque notamment selon au moins un axe de rotation correspondant au mouvement de site ou de roulis, sans generer des perturbations notamment electromagnetiques clans I'environnement du casque. A cet effet, I' invention a pour objet un dispositif de positionnement automatique selon au moins un axe de rotation d'un element susceptible d'evoluer clans un milieu sensiblement aux perturbations notamment electromagnetiques, tel qu'un casque d'aeronef par exemple, ledit dispositif comprenant au moins un mat a I'extremite duquel est articule selon un axe de rotation un support auquel peut &I-re assujetti ledit element, caracterise en ce quill comprend au moins une motorisation deportee par rapport audit axe de rotation, susceptible d'entrainer ledit axe de rotation par le biais d'une chaine cinematique ainsi qu'au moins un codeur susceptible de controler le mouvement reel dudit axe de rotation af in de compenser notamment les eventuels jeux de la chaine cinematique. b'autres caracteristiques et avantages ressortiront de la description qui va suivre de I'invention, description donnee a titre d'exemple uniquement, en regard 15 des dessins annexes sur lesquels: - la figure 1 est une representation schematique du dispositif de I'invention illustrant le mouvement de site, - la figure 2 est une representation schematique du dispositif de I'invention illustrant le mouvement de roulis, 20 - la figure 3 est une vue en perspective illustrant la partie du dispositif permettant de realiser de maniere automatique le mouvement de site, - les figures 4 et 5 sont respectivement une vue laterale et une vue en perspective illustrant la partie du dispositif permettant de realiser de maniere automatique le mouvement de roulis, 25 - la figure 6 est une vue en perspective illustrant en details la partie superieure du mat, - la figure 7 est une representation schematique illustrant un codeur selon un mode de realisation prefere de I'invention, - la figure 8 est une vue de dessus d'un disque codeur selon un mode de realisation, - la figure 9 est une vue en perspective d'un disque codeur selon un autre mode de realisation, et - la figure 10 est une vue en perspective illustrant ('emplacement d'un codeur selon une variante de realisation. Sur les figures 1 et 2, on a represents un dispositif permettant de positionner selon differentes positions un casque 10 de pilote d'aeronef, represents en pointille. To accelerate this operation, a bench has been developed comprising a motorized support for ensuring three translations Tx, Ty, Tz and a vertical rotation Rz. The other two horizontal rotations Rx corresponding to the forward / backward movement of the tate also called site and Ry corresponding to the right / left movement of the so-called rolled tate are not motorized because the environment close to the headset to be tested is a sensitive environment. electromagnetic disturbances so that the presence of a motorization to automate the rotational movements Rx and Ry is proscribed. Consequently, the operation of characterizing a helmet is relatively long and tedious because the positioning requiring a change along the axes of rotation Rx and Ry is performed manually. Also, the present invention aims to overcome the drawbacks of prior art devices by providing a device for automatic positioning of the helmet including at least one axis of rotation corresponding to the movement of the site or roll, without generating disturbances including electromagnetic Clans I helmet environment. For this purpose, the subject of the invention is an automatic positioning device according to at least one axis of rotation of an element capable of evolving in a medium substantially to disturbances, especially electromagnetic disturbances, such as an aircraft helmet for example. said device comprising at least one mat at the end of which is articulated along an axis of rotation a support to which may be subject said element, characterized in that it comprises at least a motor drive with respect to said axis of rotation, capable of driving said axis of rotation by means of a kinematic chain as well as at least one encoder capable of controlling the real movement of said axis of rotation in order to compensate in particular the possible games of the cinematic chain. Other features and advantages will become apparent from the following description of the invention, a description given by way of example only, with reference to the accompanying drawings, in which: FIG. 1 is a schematic representation of the device of the invention; 2 is a schematic representation of the device of the invention illustrating the roll motion, FIG. 3 is a perspective view illustrating the part of the device enabling the movement of the device to be made automatically. FIG. FIGS. 4 and 5 are respectively a side view and a perspective view illustrating the part of the device for automatically realizing the rolling motion; FIG. 6 is a perspective view illustrating in detail the upper part FIG. 7 is a schematic representation illustrating an encoder according to a preferred embodiment of the invention; FIG. FIG. 9 is a perspective view of an encoder disc according to another embodiment, and FIG. 10 is a perspective view illustrating the location of the encoder disc according to an embodiment. an encoder according to a variant embodiment. Figures 1 and 2, there is shown a device for positioning in different positions an aircraft pilot helmet 10, dotted.

Ce dispositif, egalement appele banc, comprend un bati 12, un support de mat 14, un mat 16 ainsi que des moyens 18 pour assujettir le casque a tester a I'extremite superieure dudit mat. La liaison entre le bati 12 et le support de mat 14 permet de realiser de maniere automatique trois translations Tx, Ty, Tz, perpendiculaires deux a deux et une rotation autour d'un axe vertical Rz. Cette liaison n'est pas plus detainee car elle est connue de I' homme du metier. Le mat 16 a une longueur suffisante pour que les elements assurant la liaison entre le bati 12 et le support de mat 14 et ceux situes au pied du mat n'induisent pas de perturbations electromagnetiques clans I'environnement du casque a tester. Comme illustre sur la figure 3, les moyens 18 pour assujettir le casque comprennent une platine 20, de forme triangulaire avec trois points d'ancrage susceptibles d'etre relies au casque a tester. Les moyens 18 pour assujettir le casque ne sont pas plus detailles car de nombreuses solutions techniques peuvent etre envisagees pour solidariser le casque au dispositif. Le mat 16 est en un materiau non metallique, notamment en matiere plastique. II comprend deux montants 22.1 et 22.2 sensiblement paralleles, fixes en partie inferieure au support de mat 14. This device, also called the bench, comprises a frame 12, a mat support 14, a mat 16 and means 18 for securing the helmet to be tested at the upper end of said mat. The connection between the frame 12 and the mat support 14 makes it possible to automatically realize three translations Tx, Ty, Tz, perpendicular two by two and a rotation around a vertical axis Rz. This connection is not more detainee because it is known to the person skilled in the art. The mat 16 has a length sufficient for the elements providing the connection between the frame 12 and the mat support 14 and those at the foot of the mat do not induce electromagnetic disturbances in the environment of the helmet to be tested. As shown in Figure 3, the means 18 for securing the helmet comprises a plate 20, of triangular shape with three anchor points may be connected to the helmet to be tested. The means 18 for securing the helmet are not more detailed because many technical solutions can be considered to secure the helmet device. The mat 16 is made of a non-metallic material, in particular of plastic material. It comprises two substantially parallel uprights 22.1 and 22.2 fixed in part below the mat support 14.

Les deux montants 22.1 et 22.2 comprennent en partie superieure des alesages clans lesquels sont susceptibles de pivoter des portees rapportees de part et d'autre d'un boitier 24, ledit boitier 24 etant susceptible de pivoter autour d'un axe de rotation Rx materialise par les portees et correspondant au mouvement de site illustre par la double fleche 26. Le dispositif comprend en partie inferieure du mat 16 une premiere motorisation 28 solidaire du support de mat 14 dont I'arbre de sortie 30 est monte en rotation clans un alesage menage au niveau d'un des montants. Des moyens de liaison permettent d'assurer la liaison cinematique entre I'arbre de sortie 30 de la premiere motorisation avec rune des portees du boitier 24 de maniere a ce que ledit boitier 24 soit entraine en rotation par la premiere motorisation 28. Selon un mode de realisation illustre en details sur la figure 3, un pignon est rapporte sur I'arbre de sortie 30 et un demi disque 32 est fixe a une portee du boitier 24, dont le centre correspond a I'axe de rotation Rx et comportant des crans en peripherie susceptibles d'engrener avec le pignon de I'arbre de sortie 30 de la premiere motorisation 28. Un premier axe de rotation 34 est monte pivotant clans le boitier 24, ledit axe de rotation 34 correspondant a I'axe de rotation Ry et etant perpendiculaire a I'axe de rotation Rx. Cet axe de rotation 34 s'etend de part et d'autre du boitier 24 et supporte une chape 36 elle-meme supportant les moyens 18 pour assujettir le casque. La chape 36 comprend deux montants dont les extremites inferieures sont reliees aux extremites du premier axe 34 et dont les extremites superieures sont reliees par une traverse sur laquelle sont rapportes les moyens 18 pour assujettir un casque a tester. The two uprights 22.1 and 22.2 comprise at the upper part of the bores in which are pivotable doorways reported on either side of a housing 24, said housing 24 being capable of pivoting about an axis of rotation Rx materialized by the door and corresponding to the movement of the site illustrated by the double arrow 26. The device comprises in the lower part of the mast 16 a first motor 28 secured to the support mat 14 whose output shaft 30 is rotated in a household bore level of one of the amounts. Connecting means make it possible to ensure the kinematic connection between the output shaft 30 of the first motorization with rune of the doors of the housing 24 so that said housing 24 is rotated by the first motor 28. embodiment shown in detail in Figure 3, a pinion is reported on the output shaft 30 and a half-disk 32 is fixed to a door of the housing 24, whose center corresponds to the axis of rotation Rx and having notches in periphery capable of meshing with the pinion of the output shaft 30 of the first motorization 28. A first axis of rotation 34 is pivotally mounted in the housing 24, said axis of rotation 34 corresponding to the axis of rotation Ry and being perpendicular to the axis of rotation Rx. This axis of rotation 34 extends on both sides of the housing 24 and supports a yoke 36 itself supporting the means 18 for securing the helmet. The yoke 36 comprises two uprights whose lower ends are connected to the ends of the first axis 34 and whose upper ends are connected by a cross on which are reported the means 18 for securing a helmet to test.

Comme illustre sur la figure 5, un second axe de rotation 38 est monte en rotation clans les portees du boitier 24, de maniere a titre coaxial a I'axe de rotation Rx. Ce second axe de rotation 38 est perpendiculaire au premier axe de rotation 34 et comprend une vis sans fin 40 susceptible d'engrener avec une roue crantee 42 solidaire du premier axe de rotation 34. b'autres solutions pourraient etre envisagees pour assurer I'entrainement en rotation du premier axe de rotation 34 par le second axe de rotation 38, par exemple un entrainement par friction. As illustrated in FIG. 5, a second axis of rotation 38 is rotated in the doorways of the housing 24 coaxially with the axis of rotation Rx. This second axis of rotation 38 is perpendicular to the first axis of rotation 34 and comprises a worm 40 capable of meshing with a notched wheel 42 integral with the first axis of rotation 34. Other solutions could be envisaged to ensure the training in rotation of the first axis of rotation 34 by the second axis of rotation 38, for example a friction drive.

Le dispositif comprend egalement en partie inferieure du mat 16 une seconde motorisation 44 solidaire du support de mat 14 dont I'arbre de sortie 46 est monte en rotation clans un alesage menage au niveau d' un des montants. Comme illustre sur la figure 4, des moyens de liaison, par exemple une courroie crantee 48, permettent d'assurer la liaison cinematique entre I'arbre de sortie 46 de la seconde motorisation 44 et un pignon rapporte a une des extremites du second axe de rotation 38 de maniere a ce que la chape 36 soit entrainee en rotation par la seconde motorisation 44 autour de I'axe Ry correspondant au mouvement de roulis illustre par la double fleche 50 sur la figure 2. Les motorisations 28 et 44 ne sont pas detaillees et sont choisies par I'homme 15 du metier. Selon une caracteristique de I' invention, tous les elements prevus entre le mat 16 et les moyens 18 pour assujettir le casque sont en des materiaux non metalliques, notamment en matiere plastique af in de pas generer des perturbations electromagnetiques clans I'environnement du casque. 20 Le fait de prevoir des motorisations 28 et 44 deportees par rapport aux axes de rotation Rx et Ry permet de ne pas generer clans I'environnement proche du casque des perturbations electromagnetiques. Ainsi, le dispositif comprend une premiere chaine cinematique comportant la premiere motorisation 28, I'arbre de sortie 30, le demi disque 32 et le boitier 24 ainsi qu'une seconde cinematique 25 comportant la seconde motorisation 44, I'arbre de sortie 46, la courroie crantee 48, le second axe de rotation 38, la vis sans fin 40, la roue crantee 42, le premier axe de rotation 34 et la chape 36. The device also comprises in the lower part of the mat 16 a second motor 44 secured to the mat support 14 whose output shaft 46 is rotated in a household bore at one of the uprights. As illustrated in FIG. 4, connecting means, for example a toothed belt 48, make it possible to ensure the kinematic connection between the output shaft 46 of the second motorization 44 and a pinion connected to one of the ends of the second axis of rotation 38 so that the yoke 36 is rotated by the second motor 44 around the axis Ry corresponding to the rolling motion illustrated by the double arrow 50 in Figure 2. The engines 28 and 44 are not detailed and are selected by those skilled in the art. According to a feature of the invention, all the elements provided between the mat 16 and the means 18 for securing the helmet are made of non-metallic materials, especially plastic material in order not to generate electromagnetic disturbances in the environment of the helmet. The provision of motors 28 and 44 with respect to the rotation axes Rx and Ry makes it possible not to generate electromagnetic disturbances in the environment close to the helmet. Thus, the device comprises a first kinematic chain comprising the first motor 28, the output shaft 30, the half-disc 32 and the housing 24 and a second cinematic 25 including the second motor 44, the output shaft 46, the toothed belt 48, the second axis of rotation 38, the worm 40, the toothed wheel 42, the first axis of rotation 34 and the yoke 36.

Selon une autre caracteristique de I' invention, chaque chaine cinematique comprend un codeur permettant de controler le mouvement reel selon chaque axe de rotation Rx et/ou Ry af in de compenser les jeux induits en raison notamment de I'elasticite des elements composant chaque chaine cinematique. According to another characteristic of the invention, each kinematic chain comprises an encoder making it possible to control the real movement along each axis of rotation Rx and / or Ry in order to compensate for the games induced, in particular because of the elasticity of the elements composing each chain. cinematic.

Ces codeurs permettent de mesurer ('evolution de la position angulaire de maniere precise ainsi qu'eventuellement le sens de rotation. Un premier codeur 52 est rapporte au niveau d'une portee du boitier 24 af in de controler ('evolution de la position angulaire autour de ('axe de rotation Rx. Un second codeur 54 est rapporte au niveau du premier axe de rotation 34 af in de controler I' evolution de la position angulaire autour de ('axe de rotation Ry. Chaque codeur comprend un disque codeur 56 ainsi que des moyens permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation. Af in de ne pas generer de perturbations notamment electromagnetiques clans 15 I'environnement du casque, le disque codeur 56 est en un materiau non metallique, et de preference en silicium. Selon un premier mode de realisation illustre sur la figure 8, le disque codeur 56 de silicium comprend sur au moins une de ses faces une pluralite de creux 58 en forme de traits, graves en surface dont I'espacement est fonction de la precision 20 souhaitee. A titre d'exemple, pour obtenir une precision de I'ordre de 0,03 , on prevoit 6000 traits sur un secteur angulaire de 180 . Selon une autre variante illustree sur la figure 9, le disque codeur 56 comprend en peripherie une pluralite d'ondulations dont le pas entre deux creux est adapte en fonction de la precision souhaitee de la mesure. 25 be preference, la profondeur des creux (graves ou des ondulations) est suffisante pour alterer le signal lorsque le faisceau eclaire un creux, ledit signal etant capte a I'interieur du creux apres une multitude de reflexions sur les parois laterales du creux. Ainsi, la profondeur du creux est independante de la longueur d'onde de I'onde revue. Selon un mode de realisation, les moyens permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation comprennent un premier couple comportant un emetteur et un recepteur pour determiner le deplacement angulaire et un second couple comportant un emetteur et un recepteur, place de maniere a recevoir un signal dephase par rapport au premier couple, pour determiner le sens de rotation du disque. Chaque couple comprend une source d'onde deportee par rapport au codeur de maniere a ne pas generer de perturbations electromagnetiques clans I'environnement du casque. Des moyens sont egalement prevus pour analyser les signaux recus par les recepteurs, lesdits moyens etant deportes par rapport aux codeurs de maniere a ne pas generer de perturbations electromagnetiques clans I'environnement du casque. These encoders make it possible to measure the evolution of the angular position in a precise manner as well as possibly the direction of rotation.A first encoder 52 is reported at a door of the housing 24 in order to control the evolution of the angular position. about a rotational axis R x A second encoder 54 is reported at the first axis of rotation 34 to control the evolution of the angular position around the axis of rotation R. Each encoder comprises an encoder disk 56 as well as means for measuring the angular movement of the disk and determining its direction of rotation In order not to generate disturbances, particularly electromagnetic disturbances in the environment of the helmet, the encoder disc 56 is made of a nonmetallic material, and preferably in silicon According to a first embodiment illustrated in FIG. 8, the silicon encoding disk 56 comprises on at least one of its faces a plurality of hollow shaped grooves 58, which are of low surface area. the spacing of which depends on the desired accuracy. By way of example, to obtain an accuracy of the order of 0.03, 6000 lines are provided over an angular sector of 180. According to another variant illustrated in FIG. 9, the encoder disk 56 comprises peripherally a plurality of corrugations whose pitch between two recesses is adapted as a function of the desired precision of the measurement. Preferably, the depth of the depressions (bass or ripples) is sufficient to alter the signal when the beam illuminates a trough, said signal being trapped within the trough after a multitude of reflections on the sidewalls of the trough. Thus, the depth of the dip is independent of the wavelength of the wave. According to one embodiment, the means for measuring the angular movement of the disk and determining its direction of rotation comprise a first pair comprising a transmitter and a receiver for determining the angular displacement and a second pair comprising a transmitter and a receiver, instead in order to receive a signal that is out of phase with the first pair, to determine the direction of rotation of the disk. Each pair includes a distorted wave source relative to the encoder so as not to generate electromagnetic disturbances in the helmet environment. Means are also provided for analyzing the signals received by the receivers, said means being deported with respect to the encoders so as not to generate electromagnetic disturbances in the environment of the headphones.

Les signaux sont transmis entre les sources d'onde et les emetteurs et entre les recepteurs et les moyens d'analyse par le biais de fibres optiques. Selon un mode de realisation prefere et illustre sur la figure 7, pour chaque codeur, les moyens permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation comprennent un seul emetteur 60 et un recepteur 62 comportant deux fibres de detection 64.1 et 64.2 placees cote a cote, une lentille de collimation 66 et deux lentilles de focalisation 68, une par fibre. Les autres extremites des fibres de detection 64.1 et 64.2 sont chacune reliees a des moyens d'analyse du signal. Selon ce mode de realisation, une source d'onde 70 sous forme d'une diode laser 25 est prevue, couplee a une fibre dont I'autre extremite est couplee a ('emetteur 60. The signals are transmitted between the wave sources and the transmitters and between the receivers and the means of analysis by means of optical fibers. According to a preferred embodiment and illustrated in FIG. 7, for each encoder, the means for measuring the angular movement of the disk and for determining its direction of rotation comprise a single transmitter 60 and a receiver 62 comprising two detection fibers 64.1 and 64.2 placed side by side, a collimation lens 66 and two focusing lenses 68, one per fiber. The other ends of the detection fibers 64.1 and 64.2 are each connected to signal analysis means. According to this embodiment, a wave source 70 in the form of a laser diode 25 is provided, coupled to a fiber of which the other end is coupled to the transmitter 60.

L'emetteur 60 comprend des moyens de collimation et de focalisation du faisceau pour obtenir une tache focale au niveau du disque codeur egale ou inferieure a 10 pm. Cette variante permet de reduire les coats puisqu'une seule source d'onde est 5 necessaire pour chaque codeur. Comme precedemment, la source d'onde 70 et les moyens d'analyse du signal sont deportes par rapport au disque codeur de maniere a ne pas generer de perturbations notamment electromagnetiques clans I'environnement du casque. Le fonctionnement du codeur est maintenant explique. 10 Lorsque le signal n'eclaire pas un creux, ledit signal est reflechi et recu par les deux fibres de detection 64.1 et 64.2, chacune recevant environ 50% du signal reflechi. Lorsque le signal eclaire un creux, le signal n'est pas reflechi si bien que les deux fibres de detection 64.1 et 64.2 ne recoivent pas de signal reflechi. 15 Lorsque le signal eclaire pour moitie un creux et une zone entre deux creux, seule une des fibres de detection recoit le signal reflechi par le disque codeur. En fonction du sens de rotation, le signal reflechi est recu par une fibre 64.1 si le disque codeur tourne clans le sens horaire, et par I'autre fibre 64.2 si le disque codeur tourne clans le sens anti-horaire. 20 be preference, le faisceau transmis par I'emetteur 60 a un angle d'incidence de I'ordre de 60 . Selon un mode de realisation, le disque codeur peut etre relie a un des axes et les moyens permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation sont relies a un ou des elements fixes. 25 Selon un mode de realisation prefere, le disque codeur du premier codeur 52, correspondant a I'axe de rotation Rx, est solidaire d'un des montants formant le mat 16. En complement, les moyens 72 permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation sont rapportes sur le boitier 24, comme illustre sur la figure 10. Selon un mode de realisation, le disque codeur du second codeur 54, correspondant a I'axe de rotation Ry, est solidaire du premier axe 34 et dispose a I'interieur du boitier 24, les moyens permettant de mesurer le mouvement angulaire du disque et de determiner son sens de rotation etant solidaires du boitier 24. Bien entendu, I'invention n'est evidemment pas Iimitee au mode de realisation represents et decrit ci-dessus, mais en couvre au contraire toutes les variantes, notamment en ce qui concerne les formes et dimensions des differents elements. Par ailleurs, bien quill soit decrit applique a un dispositif de controle d'un casque, le codeur selon I'invention pourrait etre utilise clans d'autres domaines necessitant un codeur susceptible de ne pas generer de perturbations electromagnetiques. The transmitter 60 includes means for collimating and focusing the beam to obtain a focal spot at the level of the encoder disk equal to or less than 10 μm. This variant makes it possible to reduce the costs since only one wave source is necessary for each coder. As before, the wave source 70 and the signal analysis means are deported relative to the encoder disk so as not to generate disturbances including electromagnetic environment in the helmet. The operation of the encoder is now explained. When the signal does not illuminate a trough, said signal is reflected and received by both detecting fibers 64.1 and 64.2, each receiving about 50% of the reflected signal. When the signal lights a hollow, the signal is not reflected so that the two detection fibers 64.1 and 64.2 do not receive a reflected signal. When the signal lights for half a hollow and a region between two recesses, only one of the detection fibers receives the signal reflected by the encoder disc. Depending on the direction of rotation, the reflected signal is received by a fiber 64.1 if the encoder disk rotates clockwise and by the other fiber 64.2 if the encoder disk rotates counterclockwise. Preferably, the beam transmitted by the transmitter 60 has an angle of incidence of the order of 60. According to one embodiment, the encoder disk can be connected to one of the axes and the means for measuring the angular movement of the disk and to determine its direction of rotation are connected to one or more fixed elements. According to a preferred embodiment, the encoder disk of the first encoder 52, corresponding to the axis of rotation Rx, is integral with one of the uprights forming the mat 16. In addition, the means 72 making it possible to measure the angular movement of the disk and determine its direction of rotation are reported on the housing 24, as shown in Figure 10. According to one embodiment, the encoder disk of the second encoder 54, corresponding to the axis of rotation Ry, is integral with the first axis 34 and has inside the housing 24, the means for measuring the angular movement of the disc and determine its direction of rotation being integral with the housing 24. Of course, the invention is obviously not limited to the embodiment is represented and described above, but covers all variants, especially with regard to the shapes and dimensions of the various elements. Furthermore, although it is described applied to a helmet control device, the encoder according to the invention could be used in other areas requiring an encoder likely not to generate electromagnetic disturbances.

Enf in, le dispositif de positionnement automatique selon I'invention peut permettre de positionner selon au moins un axe de rotation, tout element susceptible devolution clans un milieu sensible aux perturbations electromagnetique. Finally, the automatic positioning device according to the invention can make it possible to position, according to at least one axis of rotation, any element liable to change in a medium sensitive to electromagnetic disturbances.

Claims

1. Automatic positioning device according to at least one axis of rotation of an element likely to evolve in a medium sensitive to disturbances including electromagnetic, such as an aircraft helmet for example, said device comprising at least one mat (16). ) at the end of which is articulated along an axis of rotation a support (24, 36) to which it may be subject (edit element, characterized in that it comprises at least one engine (28, 44) relative to said axis of rotation, capable of causing said axis of rotation through a kinematic chain and at least one encoder (52,54) capable of controlling the real movement of said axis of rotation to compensate in particular the eventual games of the cinematic chain.

2. Automatic positioning device according to a first axis of rotation (Rx) corresponding to the movement of the site and a second axis of rotation (Ry) corresponding to the rolling movement of an element that can evolve in a medium sensitive to disturbances, especially electromagnetic disturbances. , such as an aircraft helmet for example, said device comprising a mast (16) at the upper end of which is articulated a housing (24) along an axis of rotation corresponding to the first axis of rotation (Rx), a clevis (36) to which said element to be tested, secured to an axis of rotation (34) pivotally mounted in said housing (24), can be connected, the rotary axis (34) corresponding to the second axis of rotation Ry and being perpendicular to the first axis of rotation Rx, characterized in that it comprises a first motor (28) deported relative to the first axis of rotation (Rx), capable of causing said first axis of rotation through a first chain cinematic, a first encoder (52) being provided for controlling the movement of said first axis of rotation and in that it comprises a second motorisation (44) displaced with respect to the second axis of rotation (Ry), able to drive said second axis of rotation by via a second cinematic chain, a second encoder (52) being provided to control the actual movement of said second axis of rotation.

3. automatic positioning device according to claim 2, characterized in that the second kinematic chain comprises a second axis of rotation (38) coaxial with the first axis of rotation (Rx), means (48) for driving in rotation (edit second axis of rotation (38) by the second motor (44), (edit second axis of rotation (38) causing in rotation the axis of rotation (34) supporting the yoke (36).

4. automatic positioning device according to claim 2 or 3, characterized in that the first kinematic chain comprises a half-disk (32) fixed to the housing (24), the center of which corresponds to the first axis of rotation (Rx) and having notches peripherally engageable with a pinion connected to the first motor (28).

5. Automatic positioning device according to any one of the preceding claims, characterized in that all the elements provided between the mat and the support for securing the element to be tested are made of nonmetallic materials, especially plastic material.

6. Positioning device according to any one of the preceding claims, characterized in that each encoder (52, 54) comprises an encoder disk (56) as well as means for measuring the angular movement of the disk and possibly determining its direction. rotation, with at least one wave source (70) and means for analyzing the signal of ports relative to the rotation axis with which they are associated.

7. bispositive of. Position according to Claim 6, characterized in that the encoder disk (56) is made of silicon.

Positioning device according to Claim 7, characterized in that the silicon encoding disc (56) comprises on at least one of its faces a plurality of grooves (58) in the form of lines, which are deep on the surface and whose spacing is function of the desired precision.

9. Positioning device according to claim 6 or 7, characterized in that the encoder disc (56) comprises peripherally a plurality of corrugations whose pitch between two recesses is adapted according to the desired precision of the measurement.

10. bispositif according to any one of claims 6 to 9, characterized in that each encoder comprises a single transmitter (60) connected to a wave source (70) and a receiver (62) having two detection fibers (64.1, 64.2) placed side by side, a collimation lens (66) and two focusing lenses (68), one per fiber, the other ends of the detection fibers (64.1, 64.2) being each connected to signal analysis, the detection fibers being arranged in such a way that when the beam emitted by the transmitter is reflected in part by a mark on the encoder disc (56) only one of the two fibers receives the reflected wave.