EP0455543B1 - Device for pointing a reflector antenna - Google Patents

Device for pointing a reflector antenna Download PDF

Info

Publication number
EP0455543B1
EP0455543B1 EP19910401103 EP91401103A EP0455543B1 EP 0455543 B1 EP0455543 B1 EP 0455543B1 EP 19910401103 EP19910401103 EP 19910401103 EP 91401103 A EP91401103 A EP 91401103A EP 0455543 B1 EP0455543 B1 EP 0455543B1
Authority
EP
European Patent Office
Prior art keywords
axis
reflector
support
lever
focus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19910401103
Other languages
German (de)
French (fr)
Other versions
EP0455543A1 (en
Inventor
Gérard Muller
Michel Souliac
Bertrand Bruneau
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MATRA ESPACE
Original Assignee
MATRA ESPACE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MATRA ESPACE filed Critical MATRA ESPACE
Publication of EP0455543A1 publication Critical patent/EP0455543A1/en
Application granted granted Critical
Publication of EP0455543B1 publication Critical patent/EP0455543B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/125—Means for positioning
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H01Q1/288—Satellite antennas

Definitions

  • the subject of the invention is a device for pointing the reflector, generally parabolic, of an antenna, making it possible to modify the orientation of the reflector by giving it a movement which can be regarded as resulting from the composition of two rotational movements around axes orthogonal to each other, orthogonal to the main axis of the reflector and passing through the focus of the reflector.
  • paraboid reflector should be taken in a broad sense and as covering not only reflectors having a shape strictly in the form of a paraboid, but those deviating little from this shape, and as covering as well reflectors having a symmetry of revolution than those formed by an eccentric dish of paraboloid.
  • the invention finds particularly important applications in the pointing of satellite antennas, where it is often necessary to supplement a rough pointing carried out by controlling the attitude of the satellite with a fine pointing, in a field corresponding to a cone whose angle at the top hardly exceeds ten degrees, (see for example GB-A-2,127,624).
  • the pointing of an antenna by rotation of its reflector around the hearth seems a priori easy to achieve by means of very diverse nature.
  • the present invention aims in particular to eliminate these defects.
  • the invention proposes in particular a device for pointing the antenna reflector by rotation relative to a support, comprising: an arm fixed to the reflector and carried by the support by means of a seal allowing it to rotate around two orthogonal axes passing through the focal point of the reflector and perpendicular to an axis of the reflector; and arm drive means having a first rotary motor of axis directed towards the focus, carried by the support and driving a first lever and a second rotary motor of axis directed towards the focus, carried by the first lever and driving a second lever connected to the arm by a link rotating on the second lever around an axis directed towards the hearth.
  • the composition of the two rotational movements around axes contributing to the focus results in a change of orientation around the focus.
  • the seal is advantageously provided so as to have only rolling links, with the exclusion of sliding links, when the conditions of use restrict the possibilities of lubrication, which is the case on a satellite.
  • the seal may in particular be constituted by a gimbal, the intermediate frame of which is hollowed out so as to leave the necessary space for the source or the receiver arranged at the focus of the reflector and fixed relative to the support.
  • the articulation bearing of the link on the second lever must tolerate slight angular deflections of the axis of rotation: in practice, the slight play that a bearing presents will often be sufficient. Otherwise, flexible blade mounting can be used.
  • the radii of the circles traversed by the axis of the second motor around the axis of the first and by the axis of the bearing around the axis of the second motor are generally chosen so that the angles at the top of the corresponding cones are each equal to half the angle at the top of the aiming cone, centered on the axis of the first engine.
  • the two levers will then have substantially the same length and will be approximately the same distance from the focal point, which makes it possible to give the antenna all the possible pointing within a cone. However, when it is possible to admit a prohibited zone in the center of the cone, it is possible to give the arms slightly different lengths.
  • the device according to the invention has many advantages.
  • the reduction is very important, the angle of which the reflector rotates being much less (often of an order of magnitude) than the angle of which one or the other of the two motors rotates.
  • the motors themselves can be made up of irreversible electric motors because they are fitted with a high ratio reducer often exceeding 100, which increases rigidity and prevents drifts.
  • the motors can be placed in the immediate vicinity of the support, which is advantageous when mounted in space since the thermal operating conditions are improved.
  • the device shown in FIG. 1 is intended to orient a reflector 10, in the form of a cap of an eccentric paraboloid of main axis 11, relative to a support 12 formed by the body of a satellite, by rotation around the focal point F , where is a source (not shown) such as a cornet.
  • the device comprises an arm 13, rigid during the implementation of the device, but which can be made up of two parts connected by a lockable articulation 14, in order to allow the folding of the arm and the application of the reflector 10 against the support 12 when launching the satellite.
  • the arm 13 is carried by the support 12 by means of a seal allowing it to take any orientation in a cone centered on the focal point F and whose apex angle 2 ⁇ corresponds to the required pointing range. In practice, the half angle at the top will hardly exceed 10 degrees. An angle of 12 degrees has been planned for a currently planned telecommunications satellite.
  • the end of the arm 13 opposite the joint 15 is fixed to the reflector 10.
  • the drive means of the arm 13 are interposed between the support 12 and an intermediate point of the arm.
  • the location of these means and their constitution are such that they do not obscure the antenna lobe.
  • they are carried by a console 18 fixed to the support and they drive a rod 20 fixed to the arm rigidly, between the hearth F and the end fixed to the reflector.
  • a first rotary motor 22, the axis of which is directed towards the focal point, can be provided to coincide with the main axis of the paraboloid when the reflector is in its middle position, and comprises a stator fixed to the console 18 and a bearing rotor a first lever 24.
  • This first lever 24 carries the stator of a second electric motor 26 of axis also directed towards the hearth F and whose rotor carries a second lever 28.
  • the latter is connected to the rod 20 by means 30 allowing a 360 ° rotation around an axis directed towards the hearth F and slight tilting movements.
  • the means 30 may consist of a bearing each time lubrication is excluded. Many bearings indeed tolerate a slight tilting. However, it is also possible to mount the bearing on the link by means of elastically deformable means, such as crossed blades.
  • the levers 24 and 28 have lengths such that the angles at the top of the cones traversed by the axis of the motor 28 and the axis of the means 30 when the motors and the motors are rotated. vertex angles equal to ⁇ .
  • the axis of the paraboloid can be given any orientation in a cone with an angle at the top 2 ⁇ . However, this condition is no longer necessary when a central dead zone can be admitted.
  • the motors 22 and 26 will generally be constituted by electric motors with reducers having a very large reduction ratio, exceeding 100/1, so as to increase the precision and the irreversibility.
  • the motors 22 and 26 can be controlled by a control circuit having a conventional general constitution, this circuit can include a calculating member supplying, from input data which can be constituted by the angles ⁇ and ⁇ (FIG. 3 ), or coordinates in x and y, the orientation, from a determined origin, to be given to motors 22 and 26.
  • this circuit can include a calculating member supplying, from input data which can be constituted by the angles ⁇ and ⁇ (FIG. 3 ), or coordinates in x and y, the orientation, from a determined origin, to be given to motors 22 and 26.
  • this singular point is located in the middle position, that is to say when the means 30 are located on the axis of the first motor, the levers 24 and 28 being then folded over one another.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Aerials With Secondary Devices (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Description

L'invention a pour objet un dispositif de pointage du réflecteur, en général parabolique, d'une antenne, permettant de modifier l'orientation du réflecteur en lui donnant un mouvement qui peut être regardé comme résultant de la composition de deux mouvements de rotation autour d'axes orthogonaux entre eux, orthogonaux à l'axe principal du réflecteur et passant par le foyer du réflecteur.The subject of the invention is a device for pointing the reflector, generally parabolic, of an antenna, making it possible to modify the orientation of the reflector by giving it a movement which can be regarded as resulting from the composition of two rotational movements around axes orthogonal to each other, orthogonal to the main axis of the reflector and passing through the focus of the reflector.

Le terme "réflecteur parabolique" doit être pris dans un sens large et comme couvrant non seulement les réflecteurs ayant une forme strictement en forme de paraboïde, mais ceux s'écartant peu de cette forme, et comme couvrant aussi bien les réflecteurs ayant une symétrie de révolution que ceux constitués par une calotte excentrée de paraboloïde.The term "parabolic reflector" should be taken in a broad sense and as covering not only reflectors having a shape strictly in the form of a paraboid, but those deviating little from this shape, and as covering as well reflectors having a symmetry of revolution than those formed by an eccentric dish of paraboloid.

L'invention trouve des applications particulièrement importantes dans le pointage des antennes de satellite, où il est souvent nécessaire de compléter un pointage grossier effectué par commande d'attitude du satellite par un pointage fin, dans un domaine correspondant à un cône dont l'angle au sommet ne dépasse guère une dizaine de degrés, (voir par exemple GB-A-2,127,624).The invention finds particularly important applications in the pointing of satellite antennas, where it is often necessary to supplement a rough pointing carried out by controlling the attitude of the satellite with a fine pointing, in a field corresponding to a cone whose angle at the top hardly exceeds ten degrees, (see for example GB-A-2,127,624).

Parmi ces applications, on peut notamment citer le pointage d'une antenne portée par un satellite géo-stationnaire, afin de diriger le lobe vers un satellite en orbite basse ou vers un récepteur ou émetteur terrestre.Among these applications, one can notably cite the pointing of an antenna carried by a geo-stationary satellite, in order to direct the lobe towards a satellite in low orbit or towards a terrestrial receiver or transmitter.

La solution consistant, dans ce dernier cas, à déplacer la source, constituée par exemple par un cornet, dans le plan focal du réflecteur est peu satisfaisante, du fait notamment de la déformation du lobe qu'elle entraîne.The solution consisting, in the latter case, in moving the source, constituted for example by a horn, in the focal plane of the reflector is unsatisfactory, due in particular to the deformation of the lobe which it causes.

Le pointage d'une antenne par rotation de son réflecteur autour du foyer semble a priori facile à réaliser par des moyens de nature très diverse. On peut par exemple fixer le réflecteur sur un bras tournant sur le support grâce à un cardan placé au foyer du réflecteur et relier le support au bras par des vérins linéaires munis de rotules.The pointing of an antenna by rotation of its reflector around the hearth seems a priori easy to achieve by means of very diverse nature. One can for example fix the reflector on an arm rotating on the support thanks to a gimbal placed at the focal point of the reflector and connecting the support to the arm by linear jacks fitted with ball joints.

Toutes ces solutions ont des inconvénients qui les rendent peu propres à remplir correctement la fonction recherchée. Par exemple, le mécanisme utilisant des vérins linéaires exige des courses importantes nuisibles à la rigidité et à la précision du pointage. Le montage direct du réflecteur sur un jeu de trois moteurs rotatifs montés en cascade est défavorable à la précision du fait de l'unicité de l'appui. En cas d'utilisation sur satellite, les moteurs sont soumis à des conditions thermiques sévères, puisqu'ils sont écartés du support. On a donc intérêt à minimiser le nombre de moteurs en série.All of these solutions have drawbacks which make them ill suited to properly fulfilling the desired function. For example, the mechanism using linear cylinders requires large strokes which are detrimental to the rigidity and accuracy of the pointing. The direct mounting of the reflector on a set of three rotary motors mounted in cascade is unfavorable to the accuracy because of the uniqueness of the support. When used on satellite, the motors are subjected to severe thermal conditions, since they are moved away from the support. It is therefore beneficial to minimize the number of motors in series.

La présente invention vise notamment à écarter ces défauts.The present invention aims in particular to eliminate these defects.

Dans ce but l'invention propose notamment un dispositif de pointage de réflecteur d'antenne par rotation par rapport à un support, comprenant : un bras fixé au réflecteur et porté par le support par l'intermédiaire d'un joint lui permettant de tourner autour de deux axes orthogonaux passant par le foyer du réflecteur et perpendiculaires à un axe du réflecteur ; et des moyens d'entraînement du bras ayant un premier moteur rotatif d'axe dirigé vers le foyer, porté par le support et entraînant un premier levier et un second moteur rotatif d'axe dirigé vers le foyer, porté par le premier levier et entraînant un second levier relié au bras par une biellette tournant sur le second levier autour d'un axe dirigé vers le foyer. La composition des deux mouvements de rotation autour d'axes concourant au foyer a pour résultante un changement d'orientation autour du foyer.To this end, the invention proposes in particular a device for pointing the antenna reflector by rotation relative to a support, comprising: an arm fixed to the reflector and carried by the support by means of a seal allowing it to rotate around two orthogonal axes passing through the focal point of the reflector and perpendicular to an axis of the reflector; and arm drive means having a first rotary motor of axis directed towards the focus, carried by the support and driving a first lever and a second rotary motor of axis directed towards the focus, carried by the first lever and driving a second lever connected to the arm by a link rotating on the second lever around an axis directed towards the hearth. The composition of the two rotational movements around axes contributing to the focus results in a change of orientation around the focus.

Le joint est avantageusement prévu pour n'avoir que des liaisons de roulement, à l'exclusion de liaisons de glissement, lorsque les conditions d'emploi restreignent les possibilités de lubrification, ce qui est le cas sur un satellite. Le joint peut notamment être constitué par un cardan dont le cadre intermédiaire est évidé de façon à laisser la place nécessaire à la source ou au récepteur disposé au foyer du réflecteur et fixe par rapport au support. Le palier d'articulation de la biellette sur le second levier doit tolérer de légers débattements angulaires de l'axe de rotation : dans la pratique, le léger jeu que présente un roulement sera souvent suffisant. Dans le cas contraire, un montage par lames flexibles peut être utilisé.The seal is advantageously provided so as to have only rolling links, with the exclusion of sliding links, when the conditions of use restrict the possibilities of lubrication, which is the case on a satellite. The seal may in particular be constituted by a gimbal, the intermediate frame of which is hollowed out so as to leave the necessary space for the source or the receiver arranged at the focus of the reflector and fixed relative to the support. The articulation bearing of the link on the second lever must tolerate slight angular deflections of the axis of rotation: in practice, the slight play that a bearing presents will often be sufficient. Otherwise, flexible blade mounting can be used.

Les rayons des cercles parcourus par l'axe du second moteur autour de l'axe du premier et par l'axe du palier autour de l'axe du second moteur sont en général choisis de façon que les angles au sommet des cônes correspondants soient chacun égaux à la moitié de l'angle au sommet du cône de pointage, centré sur l'axe du premier moteur.The radii of the circles traversed by the axis of the second motor around the axis of the first and by the axis of the bearing around the axis of the second motor are generally chosen so that the angles at the top of the corresponding cones are each equal to half the angle at the top of the aiming cone, centered on the axis of the first engine.

Les deux leviers auront alors sensiblement la même longueur et seront à peu près à la même distance du foyer, ce qui permet de donner à l'antenne tous les pointages possibles à l'intérieur d'un cône. Cependant, lorsqu'on peut admettre une zone interdite au centre du cône, il est possible de donner aux bras des longueurs légèrement différentes.The two levers will then have substantially the same length and will be approximately the same distance from the focal point, which makes it possible to give the antenna all the possible pointing within a cone. However, when it is possible to admit a prohibited zone in the center of the cone, it is possible to give the arms slightly different lengths.

Quel que soit le mode de réalisation utilisé, le dispositif selon l'invention présente de nombreux avantages. La démultiplication est très importante, l'angle dont tourne le réflecteur étant très inférieur (souvent d'un ordre de grandeur) à l'angle dont tourne l'un ou l'autre des deux moteurs. Les moteurs eux-mêmes peuvent être constitués par des moteurs électriques irréversibles parce que munis d'un réducteur de rapport élevé dépassant souvent 100, ce qui augmente la rigidité et évite les dérives. Les moteurs peuvent être placés à proximité immédiate du support, ce qui est avantageux en cas de montage dans l'espace car les conditions thermiques de fonctionnement sont améliorées.Whatever the embodiment used, the device according to the invention has many advantages. The reduction is very important, the angle of which the reflector rotates being much less (often of an order of magnitude) than the angle of which one or the other of the two motors rotates. The motors themselves can be made up of irreversible electric motors because they are fitted with a high ratio reducer often exceeding 100, which increases rigidity and prevents drifts. The motors can be placed in the immediate vicinity of the support, which is advantageous when mounted in space since the thermal operating conditions are improved.

L'invention sera mieux comprise à la lecture de la description qui suit d'un mode particulier de réalisation, donné à titre d'exemple non limitatif. La description se réfère aux dessins qui l'accompagnent, dans lesquels :

  • la figure 1 est un schéma de principe montrant les composants principaux d'un dispositif suivant l'invention ;
  • la figure 2 est une vue de détail à grande échelle montrant un montage possible des moteurs et du bras, qui est représenté en traits pleins dans l'orientation pour laquelle le réflecteur occupe sa position la plus proche du support, en traits mixtes pour la position la plus éloignée ;
  • la figure 3 est un schéma montrant la disposition des leviers portés par les moteurs pour une orientation particulière du bras.
The invention will be better understood on reading the following description of a particular embodiment, given by way of nonlimiting example. The description refers to the accompanying drawings, in which:
  • Figure 1 is a block diagram showing the main components of a device according to the invention;
  • Figure 2 is a detail view on a large scale showing a possible mounting of the motors and the arm, which is shown in solid lines in the orientation for which the reflector occupies its position closest to the support, in phantom for the position the most distant;
  • Figure 3 is a diagram showing the arrangement of the levers carried by the motors for a particular orientation of the arm.

Le dispositif montré en figure 1 est destiné à orienter un réflecteur 10, en forme de calotte de paraboloïde excentrée d'axe principal 11, par rapport à un support 12 constitué par le corps d'un satellite, par rotation autour du foyer F, où se trouve une source (non représentée) telle qu'un cornet. Le dispositif comporte un bras 13, rigide lors de la mise en oeuvre du dispositif, mais pouvant être constitué en deux parties reliées par une articulation verrouillable 14, afin d'autoriser le repliement du bras et l'application du réflecteur 10 contre le support 12 lors du lancement du satellite.The device shown in FIG. 1 is intended to orient a reflector 10, in the form of a cap of an eccentric paraboloid of main axis 11, relative to a support 12 formed by the body of a satellite, by rotation around the focal point F , where is a source (not shown) such as a cornet. The device comprises an arm 13, rigid during the implementation of the device, but which can be made up of two parts connected by a lockable articulation 14, in order to allow the folding of the arm and the application of the reflector 10 against the support 12 when launching the satellite.

Le bras 13 est porté par le support 12 par l'intermédiaire d'un joint lui permettant de prendre n'importe quelle orientation dans un cône centré sur le foyer F et dont l'angle au sommet 2α correspond à la plage de pointage nécessaire. Dans la pratique, le demi angle au sommet dépassera peu 10 degrés. Un angle de 12 degrés a été prévu pour un satellite de télécommunication à l'heure actuelle en projet.The arm 13 is carried by the support 12 by means of a seal allowing it to take any orientation in a cone centered on the focal point F and whose apex angle 2α corresponds to the required pointing range. In practice, the half angle at the top will hardly exceed 10 degrees. An angle of 12 degrees has been planned for a currently planned telecommunications satellite.

Etant donné que le fonctionnement dans l'espace restreint la possibilité de lubrification du joint, ce dernier sera d'un type n'ayant pas de liaison de glissement. Une solution satisfaisante consiste à utiliser un joint de cardan à roulements 15 porté par le support 12 et dont le cadre intermédiaire 16 est évidé pour laisser la place nécessaire à la source, non représentée.Since operation in space limits the possibility of lubrication of the seal, this the latter will be of a type having no slip link. A satisfactory solution consists in using a universal joint with bearings 15 carried by the support 12 and whose intermediate frame 16 is hollowed out to leave the necessary space for the source, not shown.

L'extrémité du bras 13 opposée au joint 15 est fixée au réflecteur 10.The end of the arm 13 opposite the joint 15 is fixed to the reflector 10.

Les moyens d'entraînement du bras 13 sont interposés entre le support 12 et un point intermédiaire du bras. L'emplacement de ces moyens et leur constitution sont tels qu'ils n'occultent pas le lobe d'antenne. Dans le cas illustré ils sont portés par une console 18 fixée au support et ils entraînent une biellette 20 fixée au bras de façon rigide, entre le foyer F et l'extrémité fixée au réflecteur.The drive means of the arm 13 are interposed between the support 12 and an intermediate point of the arm. The location of these means and their constitution are such that they do not obscure the antenna lobe. In the illustrated case they are carried by a console 18 fixed to the support and they drive a rod 20 fixed to the arm rigidly, between the hearth F and the end fixed to the reflector.

Un premier moteur rotatif 22, dont l'axe est dirigé vers le foyer, peut être prévu pour coïncider avec l'axe principal du paraboloïde lorsque le réflecteur est dans sa position médiane, et comporte un stator fixé à la console 18 et un rotor portant un premier levier 24. Ce premier levier 24 porte le stator d'un second moteur électrique 26 d'axe également dirigé vers le foyer F et dont le rotor porte un second levier 28. Ce dernier est relié à la biellette 20 par des moyens 30 autorisant une rotation de 360° autour d'un axe dirigé vers le foyer F et de légers mouvements de basculement. Dans la pratique, les moyens 30 peuvent être constitués par un roulement chaque fois que la lubrification est exclue. Beaucoup de roulements tolèrent en effet un léger basculement. Il est cependant également possible de monter le roulement sur la biellette par l'intermédiaire de moyens déformables élastiquement, tels que des lames croisées.A first rotary motor 22, the axis of which is directed towards the focal point, can be provided to coincide with the main axis of the paraboloid when the reflector is in its middle position, and comprises a stator fixed to the console 18 and a bearing rotor a first lever 24. This first lever 24 carries the stator of a second electric motor 26 of axis also directed towards the hearth F and whose rotor carries a second lever 28. The latter is connected to the rod 20 by means 30 allowing a 360 ° rotation around an axis directed towards the hearth F and slight tilting movements. In practice, the means 30 may consist of a bearing each time lubrication is excluded. Many bearings indeed tolerate a slight tilting. However, it is also possible to mount the bearing on the link by means of elastically deformable means, such as crossed blades.

Dans un mode avantageux de réalisation, les leviers 24 et 28 ont des longueurs telles que les angles au sommet des cônes parcourus par l'axe du moteur 28 et l'axe des moyens 30 lors de la mise en rotation des moteurs et des angles au sommet égaux à α. Dans ce cas, on peut donner à l'axe du paraboloïde n'importe quelle orientation dans un cône d'angle au sommet 2α. Cependant, cette condition n'est plus nécessaire lorsque l'on peut admettre une zone centrale morte.In an advantageous embodiment, the levers 24 and 28 have lengths such that the angles at the top of the cones traversed by the axis of the motor 28 and the axis of the means 30 when the motors and the motors are rotated. vertex angles equal to α . In this case, the axis of the paraboloid can be given any orientation in a cone with an angle at the top 2 α . However, this condition is no longer necessary when a central dead zone can be admitted.

Dans la pratique, cela conduira à des longueurs presque égales pour les leviers 24 et 28, d'axe à axe.In practice, this will lead to almost equal lengths for the levers 24 and 28, from axis to axis.

Les moteurs 22 et 26 seront généralement constitués par des moteurs électriques à réducteurs présentant un rapport de réduction très important, dépassant 100/1, de façon à augmenter la précision et l'irréversibilité.The motors 22 and 26 will generally be constituted by electric motors with reducers having a very large reduction ratio, exceeding 100/1, so as to increase the precision and the irreversibility.

Les moteurs 22 et 26 peuvent être commandés par un circuit d'asservissement ayant une constitution générale classique, ce circuit peut comporter un organe de calcul fournissant, à partir de données d'entrée qui peuvent être constituées par les angles ϑ et φ (figure 3), ou des coordonnées en x et y, l'orientation, à partir d'une origine déterminée, à donner aux moteurs 22 et 26.The motors 22 and 26 can be controlled by a control circuit having a conventional general constitution, this circuit can include a calculating member supplying, from input data which can be constituted by the angles ϑ and φ (FIG. 3 ), or coordinates in x and y, the orientation, from a determined origin, to be given to motors 22 and 26.

Il faut seulement remarquer qu'il existe, dans la plage de débattements possible, un point singulier à travers lequel il n'est pas toujours possible de passer en poursuivant le déplacement de l'axe du réflecteur de façon continue : le passage par ce point implique d'effectuer une rotation des leviers 24 et 28 de 180°. Ceci n'est pas dommageable au mouvement mais implique une rotation rapide du premier moteur, de l'ordre de 180° pour un déplacement du réflecteur de l'ordre de quelques degrés autour du point singulier.It should only be noted that there exists, in the range of possible deflections, a singular point through which it is not always possible to pass while continuing the displacement of the axis of the reflector in a continuous way: the passage by this point involves rotating the levers 24 and 28 by 180 °. This is not harmful to the movement but implies a rapid rotation of the first motor, of the order of 180 ° for a displacement of the reflector of the order of a few degrees around the singular point.

Dans le cas où les leviers 24 et 28 sont de même longueur, ce point singulier est situé en position médiane, c'est-à-dire lorsque les moyens 30 sont situés sur l'axe du premier moteur, les leviers 24 et 28 étant alors repliés l'un au-dessus de l'autre.In the case where the levers 24 and 28 are of the same length, this singular point is located in the middle position, that is to say when the means 30 are located on the axis of the first motor, the levers 24 and 28 being then folded over one another.

Pour que la singularité n'apparaisse pas au cours d'un mouvement passant par le point singulier, il faut que les leviers puissent s'approcher, puis s'éloigner de la normale à la trajectoire de manière continue. Ceci implique que les courbes ainsi décrites soient une fois continûment dérivables (courbes dites de classe C¹) au point singulier.So that the singularity does not appear during a movement passing through the singular point, the levers must be able to approach and then move away from the normal to the trajectory continuously. This implies that the curves thus described are once continuously differentiable (so-called class C¹ curves) at the singular point.

Dans le cas d'un mouvement quelconque partant du point singulier, ou passant par ce point hors des conditions précédemment énoncées, il est nécessaire de faire tourner le levier 24, entraînant le moteur 26 et le levier 28, de manière à le mettre perpendiculaire à la trajectoire avant que tout mouvement du réflecteur soit entrepris. Ces mouvements sont facilités si on laisse le second moteur tourner de 360°, alors que 180° seraient théoriquement suffisants.In the case of any movement starting from the singular point, or passing through this point outside the conditions previously stated, it is necessary to rotate the lever 24, driving the motor 26 and the lever 28, so as to put it perpendicular to the trajectory before any movement of the reflector is undertaken. These movements are facilitated if the second motor is allowed to rotate 360 °, while 180 ° would be theoretically sufficient.

Claims (6)

  1. A device for sighting the reflector (10) of an antenna by rotation in relation to a support (12), comprising an arm (13) attached to the reflector and carried by the support, via a joint (15) enabling it to rotate around two axes which are orthogonal to one another and pass through the focus of the reflector and are perpendicular to an axis of the reflector and means for driving the arm, characterized in that said means have a first rotary motor (22) the axis of which is directed towards the focus, carried by the support (12) and driving a first lever (24), and a second rotary motor (26) the axis of which is directed towards the focus, carried by the first lever and driving a second lever (28) connected to the arm via a rod (20) rotating on the second lever (28) around an axis directed towards the focus.
  2. A device according to Claim 1, characterized in that the joint has solely rolling links, to the exclusion of sliding links.
  3. A device according to Claim 2, characterized in that the universal joint is formed by a cardan whose intermediate frame (16) leaves the space required for a source for a receiver disposed at the focus of the reflector and fixed in relation to the support.
  4. A device according to Claim 1, 2 or 3, characterized in that the rod (20) is mounted on the second lever via a roller bearing (30) which accommodates angular movements in planes passing through the axis of rotation.
  5. A device according to any of Claims 1 to 4, characterized in that the radii of the circles through which the axis of the second motor extends around the axis of the first motor and through which the axis of the bearing extends around the axis of the second motor are such that the angles at the apex of the corresponding cones (α) are each equal to half the angle (2α) at the apex of the sighting cone.
  6. A device according to any of the preceding Claims characterized in that the motors (22, 26) are located immediately adjacent the support.
EP19910401103 1990-04-30 1991-04-25 Device for pointing a reflector antenna Expired - Lifetime EP0455543B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9005479A FR2661560B1 (en) 1990-04-30 1990-04-30 POINTING DEVICE FOR AN ANTENNA REFLECTOR.
FR9005479 1990-04-30

Publications (2)

Publication Number Publication Date
EP0455543A1 EP0455543A1 (en) 1991-11-06
EP0455543B1 true EP0455543B1 (en) 1994-08-10

Family

ID=9396222

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910401103 Expired - Lifetime EP0455543B1 (en) 1990-04-30 1991-04-25 Device for pointing a reflector antenna

Country Status (3)

Country Link
EP (1) EP0455543B1 (en)
DE (1) DE69103322D1 (en)
FR (1) FR2661560B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2039164B1 (en) * 1992-01-30 1997-01-01 Sener Ing & Sist HIGH PRECISION ADJUSTMENT MECHANISM FOR THE CORRECT POSITIONING OF DEFORMABLE STRUCTURES.

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2502404A1 (en) * 1981-03-20 1982-09-24 Matra Articulated mounting for satellite sub-assembly - uses output from inertial detector to control step or torque motor to move support arm for stabilisation
US4550319A (en) * 1982-09-22 1985-10-29 Rca Corporation Reflector antenna mounted in thermal distortion isolation
DE3411838A1 (en) * 1984-03-30 1985-10-10 ANT Nachrichtentechnik GmbH, 7150 Backnang Pivoting beam antenna for space radio stations
FR2578687B1 (en) * 1985-03-05 1988-06-10 Hardricourt Constr Blindees DEVICE FOR SUPPORTING AND ADJUSTING A RADAR, PARTICULARLY ON A VEHICLE OR ON A SHELTER, AND PARTICULARLY AN ARMORED VEHICLE
DE3835316A1 (en) * 1988-10-17 1990-04-19 Neuberger Nachrichten Und Ante Parabolic antenna holder

Also Published As

Publication number Publication date
DE69103322D1 (en) 1994-09-15
FR2661560B1 (en) 1992-08-07
FR2661560A1 (en) 1991-10-31
EP0455543A1 (en) 1991-11-06

Similar Documents

Publication Publication Date Title
EP2630379B1 (en) Compact flexible cardan joint and spacecraft comprising such a joint
EP2256039B1 (en) Through-pivot with flexible elements and spacecraft comprising such a pivot
WO1999038044A1 (en) Assembly for mounting and correcting the position of an element, such as a mirror, of a space telescope
EP1964778B1 (en) Pivot with blades
EP0295978B1 (en) Method and device for positioning a spacecraft in the direction of a celestial body
EP2706267B1 (en) Angular positioning device comprising two interleaved mechanical assemblies for movement transmission, with two dead centres each
EP0455543B1 (en) Device for pointing a reflector antenna
EP3947158B1 (en) Device for deploying and pointing an item of equipment carried by a spacecraft
FR2646023A1 (en) Antenna pointing device, satellite equipped with such a device and antenna pointing process using such a device
FR2835579A1 (en) SPHERIC ELEMENT DISPLACEMENT DEVICE
EP1635485B1 (en) Optical transmission method between an on-board spacecraft terminal and a distant terminal, and spacecraft adapted for said method
EP0056550A2 (en) Device for orientation according to two orthogonal axes, in particular for a microwave antenna
EP3947160B1 (en) Geostationary satellite comprising a radiator with reduced insolation and improved guidance system
CA2060773C (en) Support and rotative driving device for a live load in relation to a structure, particularly for a pointing mechanism for a satellite antenna
WO2016066395A1 (en) Device for adjusting a mobile element such as an antenna deck
EP2703691B1 (en) Apparatus for angular positioning with three dead centers
EP3870408B1 (en) Method for causing a tool at the end of an articulated arm to press without slipping against a surface, and device for implementing same
FR3047114A1 (en) ANTENNA REFLECTOR ASSEMBLY WITH FIXED SOURCE ADAPTED TO BE MOUNTED ON A SATELLITE
FR2663789A1 (en) DEVICE FOR MOVING AN ORGAN AND APPLICATION FOR POINTING AN ANTENNA REFLECTOR.
CA2225583A1 (en) Optical observation system comprising an inclined, two-sided sighting/scanning mirror
FR2876926A1 (en) DEVICE AND INSTALLATION FOR FOLDING A FLAN

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES GB IT NL SE

17P Request for examination filed

Effective date: 19911209

17Q First examination report despatched

Effective date: 19931208

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES GB IT NL SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19940810

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19940810

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19940810

REF Corresponds to:

Ref document number: 69103322

Country of ref document: DE

Date of ref document: 19940915

ITF It: translation for a ep patent filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19941110

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19941111

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19960419

Year of fee payment: 6

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19970425

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19970425

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050425