Data transmission device

Abstract

The invention relates to a data transmission device (10) comprising at least two concentric drums (101, 102) freely rotating about an axis of rotation (Ar), and at least two wired communication elements (104), each drum (101, 102, 103) comprising a set of walls forming in common two by two at least two concentric housings (106) such that each housing (106) comprises an inner side wall (160) formed by one of the drums (101, 102) and an outer side wall (161) formed by the other or one of the other drums (101, 102), each wired data transmission element (104) being disposed in one of the housings (106), each wired communication element (104) comprising a movable part (140) disposed between a first fixed part (141) and a second fixed part (142),the first fixed part (141) being (143) fixed to the inner wall (160) of one of the housings (106) and the second fixed part (142) being fixed to the outer wall (161) of said housing (106). Figure for the abbreviation: Figure 2,

Description

Title of the invention: Data transmission device

[0001] The invention relates to data transmission devices, in particular for optronic recognition and surveillance systems.

[0002] There are a large number of optronic systems in the world for aerial reconnaissance and surveillance, which are essentially dedicated aerial reconnaissance pods, laser designator and attack pods, and gyrostabilized or non-gyrostabilized optronic balls.

[0003] Optronic systems can be mounted on aircraft, drones, balloons or helicopters, among other things.

[0004] Optronic systems generally comprise a head mounted articulated on a body. The head includes the monitoring and targeting instruments and has a pan and tilt joint ("Pan & Tilt" in English) capable of pivoting on two axes: horizontally (pan or roll) and vertically (tilt or elevation).

[0005] Optronic systems include a data transmission system that transfers data from the head-to-body instruments to the carrier vehicle. The quality of this data transmission and the robustness of the system over time are crucial for optronic system applications. One challenge in this transmission lies at the head articulation point.

[0006] For this purpose, it is known to use coaxial cables which must be carefully arranged to allow free rotation of the head while maintaining a reliable connection for data transmission.

[0007] In particular, they can be arranged in loops or spirals to allow for some flexibility during rotation of the system head. They can also be guided by sheaths or conduits to protect and hold them in place. Arranging them in a rotating collector is also known.

[0008] Nevertheless, the ever-increasing quality of surveillance and targeting instruments implies an adaptation of transmission systems in order to transmit an ever-increasing amount of information and in increasingly smaller spaces.

[0009] The invention aims to provide a reliable and robust data transmission device over time which has a large data transmission capacity and is compact.

[0010] To this end, the invention relates to a data transmission device comprising: - at least two concentric drums free to rotate around an axis of rotation, and - at least two wired communication devices,

[0011] each drum comprising a set of walls forming in common two by two at least two concentric housings such that each housing comprises an internal side wall formed by one of the drums and an external side wall formed by the other or one of the other drums,

[0012] each wired data transmission device being disposed in one of the housings, each wired communication device comprising a mobile part disposed between a first fixed part and a second fixed part, the first fixed part being fixed to the internal wall of one of the housings and the second fixed part being fixed to the external wall of said housing.

[0013] The data transmission device of the invention has the advantage of being able to wind and unwind at least two assemblies of optical fibers. The use of optical fiber assemblies makes it possible to obtain a greater data transmission capacity in a smaller volume compared to prior art transmission methods.

[0014] The transmission device of the invention can be arranged in any system involving two drums rotating about the same axis and through which data must be transmitted. The invention finds particular application in the context of optronic recognition and surveillance systems.

[0015] According to one embodiment of the invention, the device comprises at least three concentric drums.

[0016] In particular, at least two of the dwellings include a common side wall, where at least two wired communication devices each include one of their fixed parts attached to said or one of said common walls, and where said fixed parts attached to said or one of said common walls are connected to each other by a linking device.

[0017] According to one embodiment of the invention, the wired communication means comprise at least one optical fiber assembly and / or at least one copper cable assembly.

[0018] In particular, the wired communication means (104) comprise at least one optical fiber assembly, the moving part of which is in the form of at least one strip comprising an upper surface and a lower surface, the upper surface being free and the lower surface being in contact with the inner and outer walls of one of the housings. Thus, according to this aspect of the invention, the moving part of the optical fiber assembly does not wind itself but Fold with the upper surface facing itself along its entire length. This greatly reduces tension on the fibers and thus better preserves them for improved durability.

[0019] According to one embodiment of the invention, at least the lower part of said at least one belt is smooth. This aspect of the invention reduces friction between the belts and thus delays, or even prevents, their degradation due to drum rotations.

[0020] According to one embodiment of the invention, said at least one optical fiber strip exhibits reversible elastic properties. Thus, the optical fiber strips do not tend to deform in a direction perpendicular to the winding, and are better preserved over time.

[0021] According to one embodiment, the optical fibers of said at least one strip are bonded together. This bonding allows for better cohesion between the optical fibers so as to increase the resistance of the assembly to torsional forces during winding movements.

[0022] According to one embodiment, said at least one strip comprises a support on which the optical fibers are glued.

[0023] According to one embodiment, said at least one optical fiber strip is pressed against the inner wall and the outer wall of one of the housings.

[0024] The invention also relates to an optronic recognition and surveillance system comprising a data transmission device as defined above. Brief description of the figures

[0025] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0026] Fig. 1 represents an isometric view of an optronic recognition and surveillance system comprising a data transmission device according to the invention.

[0027] Fig. 2 represents an isometric view of a data transmission device according to a first embodiment of the invention.

[0028] Fig. 3 represents a cross-sectional view along axis AA of the device of Fig. 2.

[0029] Figure 4 shows a cross-sectional view of a data transmission device according to a second embodiment of the invention.

[0030] Figure 5 represents an isometric view of a data transmission device according to a third embodiment of the invention.

[0031] Fig. 6 represents a cross-sectional view along axis BB of the device of Fig. 5.

[0032] Figure 7 represents a cross-sectional view of a data transmission device according to a fourth embodiment of the invention. Detailed description of the invention

[0033] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. The features of different embodiments can also be combined and / or interchanged to provide other embodiments.

[0034] The invention relates to a data transmission device 10 particularly adapted for an optronic recognition and surveillance system 30. Figure 1 shows an example of such a recognition system 30 comprising a designation and recognition pod 30 including a head 301 articulated by a panoramic and tilt joint with a body 302. The head 301 includes measuring instruments 310 whose information is to be transmitted to the body 302 through said joint. The panoramic and tilt joint includes a first pivot joint 303 and a second pivot joint 304 arranged at 90 degrees to each other. The first pivot joint 303 has a rotation limit of less than 360 degrees, in particular 240 degrees, whereas the second pivot joint 304 has no rotation limit. The data transmission device 10 of the invention (not visible in Figure 1) is shown.l]) is notably mounted at the first pivot link 303 of the head 301 of the optronic reconnaissance and surveillance system 30. .

[0035] The transmission device 10 comprises at least two drums 101, 102, 103 and at least two wired communication elements 104. The device 10 comprises an upper surface 107 and a lower surface 108 that are opposite each other and transverse to the axis Ar. The terms "upper" and "lower" do not, in this description, imply a limit to the spatial orientation of the device 10 or any component thereof, but simply a notion of spatial opposition. The communication elements 104 pass through the device 10 from one side to the other along the direction of the axis Ar by means of at least one opening 109 located in the upper surface 107 and at least one opening 109 located in the lower surface 108.

[0036] The drums 101, 102, and 103 are arranged concentrically and freely rotate independently about an axis of rotation Ar, which here corresponds to the pivot joint 303. In the embodiment shown in Figures 1 and 2, two drums are present. In the embodiments shown in Figures 4-6, three drums are present. Regardless of the embodiment, the device comprises always an outer drum 101, an inner drum 101 and optionally one or more intermediate drums 103.

[0037] The drums 101, 102, 103 have, in particular, a relative rotation limit of less than 360 degrees, specifically 240 degrees. This limitation is achieved by any means, and in particular by a stop (not shown) designed to cooperate with the surrounding elements of the system in which the device 10 is installed, or with the adjacent drum(s) 101, 102, 103. The drums 101, 102, 103 rotate relatively between the maximum permissible angles.

[0038] The inner drum 102 and outer drum 101 will first be described with reference to Figures 2-3. In the embodiment shown, the outer drum 101 extends around the inner drum 102, which is itself circumscribed around the outer drum 101. The inner drum 102 comprises a body 122 articulating with the pivot joint 303. The outer drum 101 comprises a body 111 that can articulate directly with the pivot joint 303 or with the inner drum 102, notably via a bearing 105. The body 122 of the inner drum 102 includes, in particular, a tubular projection 123 extending along the axis Ar and traversed by a central opening 121 into which the pivot joint 303 is inserted.

[0039] We will now turn to Figures 4-6, which illustrate three embodiments comprising an intermediate drum 103. An intermediate drum 103, like the outer drum 101, can be articulated directly with the pivot joint 303 or with at least some of the other drums 101, 102, 103, notably via one or more bearings 105. Thus, as can be seen in Figures 4 and 6, the intermediate drum 103 can be articulated either with the inner drum 102 and the outer drum 103 ([Fig. 4]), or with only one of the two ([Fig. 6]). Furthermore, the difference between the second and the third and fourth embodiments shown in these figures lies in the configuration of the communication members 104, described in detail below. For the remainder of this discussion, Figures 2-6 will be read together.

[0040] The various drums 101, 102, 103 each comprise a set of walls 110, 120, 130. The configuration of these sets of walls 110, 120, 130 allows for the formation of at least two compartments 106, each designed to receive at least one of the communication elements 104. Each compartment 106 thus defines a space where the communication elements 104 can wind and unwind during the respective rotations of the drums 101, 102, 103 around the axis Ar. The openings 109 in the upper and lower surfaces 107, 108 of the device 10 thus open onto the compartments 106 for the passage of the communication elements 104.

[0041] The housings 106 are arranged concentrically around the axis Ar, and in particular around the tubular projection 123 of the internal drum 102.

[0042] Each dwelling 106 is delimited by lateral walls, namely an internal wall 160 and an external wall 161, one of which belongs to one of the drums 101, 102, 103 and the other to another drum 101, 102, 103. The term "internal wall" refers to the wall of the dwelling 106 that is closest to the axis Ar, and in particular to the central light 121. Conversely, the term "external wall" refers to the wall of the dwelling 106 that is furthest from the axis Ar, and in particular from the central light 121. The internal and external walls 160, 161 of the dwellings 106 thus extend along the axis Ar and are followed transversely to the axis Ar. Each dwelling 106 may have internal and external walls 160, 161 distinct from the other dwellings 106, or alternatively, at least two dwellings may share one of the side walls 160, 161, then called common wall 165. Each drum 101, 102, 103 forms a wall 160, 161 of at least one of the dwellings 106.Thus a drum 101, 102, 103 can form several walls 160, 161 but with different housings 106.

[0043] In addition to the internal and external walls 160, 161, each housing 106 comprises a first transverse wall 162 and / or a second transverse wall 163, the first and second transverse walls 162, 163 being opposite each other and connected to the internal and external walls 160, 161. A wall 162, 163 may in particular comprise the upper surface 107 or lower surface 108 of the device 10. The first transverse wall 162 and / or the second transverse wall 163 of a housing 106 may be formed by different elements of the device 10, namely a wall 110, 120, 130 of a drum 10, 102, 103, a bearing 105, or a combination thereof. The housing 106 includes at least one opening 164 for the passage of the communication organs 104 which is fitted in a wall 110, 120 or 130 forming at least part of said wall 162, 163, as shown in [Fig.2].For obvious operational reasons, the wall 110, 120, 130 in which the opening 164 is located belongs to the drum 101, 102, 103 forming the wall 160, 161 to which the communication element(s) 104 passing through the opening 164 are attached. The interaction between the communication elements 104 and the drums 101, 102, 103 is described in detail later. The housing 106 can be completely open on one side so that it does not include a first transverse wall 162 or a second transverse wall 163, but instead an opening 164, as can be seen, for example, in Figures 2 to 6. The openings 164 lead onto, or correspond to, the opening(s) 100.

[0044] When an intermediate drum 103 includes a wall 130 forming a common wall 165 for two housings 106, it can also carry a connecting member 150 connecting two communication elements 104, as shown in Figures 5-7. The connecting element 150 is notably connected to one of the fixed parts 141, 142 of each communication element 104, or to their moving part 140, these fixed parts 141, 142 and moving parts 140 being described in detail below. The connecting element 150 is notably in the form of at least one assembly of optical fibers and / or at least one assembly of copper cables passing through or around the common wall 165, as shown in Figures 5-6. This aspect of the invention advantageously allows the possible winding and unwinding angle of the communication elements 104 to be increased tenfold by connecting them together.Indeed, in a first housing 106, a first communication element 104 can be wound / unwound at a certain angle, then a second element 104, located in a second adjacent housing 106 and connected to the first, can take over the winding / unwinding. Naturally, the various drums 101, 102, 103 forming the adjacent housings 106, in which the various interconnected communication elements 104 are in motion, are coordinated with each other. This coordination can be achieved by any means, particularly using sets of stops, and prevents the rotation of one of the drums 101, 102, 103 from pulling on a communication element 104 located in a housing 106 that it does not form, and causing it to tear.

[0045] The communication organs 104 may include at least one optical fiber assembly and / or at least one copper cable assembly.

[0046] The communication members 104 each comprise a movable part 140 disposed between a first fixed part 141 and a second fixed part 142. The first fixed part 141 is fixed to the inner wall 160 of a housing 106, and the second fixed part 142 is fixed to the outer wall 161 of said housing 106. This fixing can be done by any means, and in particular by screwing and / or by gluing. As previously seen, the first fixed part and the second fixed part 141, 142 can pass through the first transverse wall 162 and the second transverse wall 163 respectively through at least one opening 164. The first 141 and the second 142 fixed parts each include in particular an end fixed to the wall 160, 161 of the housing 106 and a free end including in particular a connection means, such as a plug 149, for the continuity of data transmission with other devices.

[0047] The moving part 140 winds and unwinds in the housing 106 according to the relative rotational movements of the drums 101, 102, 103. A first end 143 of the moving part 140 is connected to the first fixed part 141, and a second end 144 of the moving part 140 is connected to the second fixed part 142. These connections can be made by any means, and in particular by means of sets of plugs. Thus, the first end 143 is fixed to the wall 160, 161 of the housing 106 by its connection to the first fixed part 141, and the second end 144 is fixed to the wall 160, 161 of the housing 106 by its connection to the second fixed part 142.

[0048] The first end 143 and the second end 144 of the movable part 140 are arranged at the same height within the housing 106, so as to prevent any torsion at rest of the fixed parts 141, 142 and / or of the movable part 140, which would be all the more pronounced during successive rotations. Such torsion could, in the long term, cause damage to the communication components and the associated loss of information.

[0049] In order to guide the winding and unwinding of the optical fiber assemblies 103 during successive rotations of the drums 101, 102, the inner wall 160 and / or the outer wall 161 of at least one of the housings 106 may include guide elements 115, 127, as shown in Figures 3-6. Said guide elements 115, 127 are in particular in the form of one or more channels parallel to the direction of rotation of the drums 101, 102, or transversely to the axis Ar.

[0050] The moving part 140 of at least one of the communication elements 103 may be in the form of one or more bands 145, as shown in Figures 2 to 7. When several bands 145 are present, the first and second fixed parts 141, 142 of a communication element 103 may also have several parts, so that the first ends 143 and second ends 144 of each band 145 may be at least partially connected to the same fixed part 141, 142 or each connected to its own fixed part 141, 142. The different parts of the fixed parts 141, 142 may be fixed at different levels and locations on the inner wall 160 and the outer wall 161 of the housing 106, but are preferably fixed at the same level for the same band 145. All the bands 145 may also be connected to the same single fixed parts 141, 142, as shown in [Fig.2].The various strips 145 are notably spaced apart and aligned side by side along the walls 160, 161, as shown in this figure. Alternatively, they can be superimposed on each other, with an intervening space.

[0051] In particular, said at least one strip 145 comprises a free portion 146 disposed between a first portion 147 in contact with the inner wall 160 of the housing 106 and a second portion 148 in contact with the outer wall 161 of the housing 106. During the relative rotation of the drums 101, 102, the free portion 146 has, in particular, the same dimensions, while the contact portions 147, 140 will alternately shorten in favor of the lengthening of the other depending on the direction of relative rotation of the drums 101, 102.

[0052] Within an assembly 103, each strip 145 may have its own length, or all the strips 145 may have the same length. Naturally, the length of said at least one strip 145 is adapted so as not to impede the relative rotation of the drums 101, 102.

[0053] When several strips 145 are present, they can be placed separately in parallel channels 115, 127 at the drums 101, 102, as shown in Figures 3-6. In particular, two channels 115, 127 are separated by a partition 118, 123. This feature improves the guidance of the optical fibers to different channels. The partition can be made of the same material as the channel, a metallic material, or any other material (organic, for example).

[0054] According to one embodiment, said at least one strip 145 can be configured so that the contact parts 147, 148 are pressed against the respective inner 160 and outer 161 walls. This feature makes it possible to limit, or even prevent, creasing at these parts 147, 148, which can lead to damage to the communication components and associated loss of information.

[0055] The position of said at least one strip 145 in the housing 106 can be configured so that it does not curl up on itself and risk being damaged by crushing during the relative rotation of the inner drum 101 and outer drum 102. To this end, said at least one strip 145 comprises an upper surface and a lower surface opposite each other, the lower surface being in particular the only surface in contact with the inner and outer walls 160, 161 of the housing 106. Thus, the upper surface is folded back on itself along the entire length of the strip 145. The housing 106 is specifically adapted so that the upper surface of the strip 145 is not folded back on itself during the relative rotation of the drums 101, 102. These various aspects help to preserve the integrity of the optical fibers. The lower surface is particularly smooth in order to reduce its degradation during successive rotations of drums 101, 102.

[0056] Said at least one strip 145 can in particular be configured so as not to bend in a direction perpendicular to the winding during the rotations of the drums 101, 102. Indeed, during the rotations of the drums 101, 102, said at least one strip will be pulled or pushed depending on the direction of rotation, resulting in torsional forces on the free part 146 and / or the contact parts 147, 148. If the strip 145 is not sufficiently resistant in a direction perpendicular to the winding, it can bend in this direction over successive rotations. This folding can then lead to damage to the communication components, resulting in an associated loss of information.

[0057] In optical fiber assemblies, the reduction, or even the absence, of bending at the contact parts 147, 148 and the free part 146, as well as the pressing of the contact parts 147, 148 against the respective internal 160 and external 161 walls, can be ensured by a cohesion of the optical fibers along the width of the strip 145 that is sufficient to produce reversible elastic properties. Thus, these properties allow the strip 145 to absorb torsional forces, and even if the strip 145 undergoes torsion, it returns to its original shape once the torsion has ceased.

[0058] This cohesion can be ensured in particular by bonding the optical fibers together. The adhesive can be applied to the upper and / or lower surface of the strip 145. Preferably, the adhesive is applied to the lower surface, which will be in contact with the walls 160, 161 of the housings 106, in order to limit possible degradation of the optical fibers.

[0059] Alternatively or in addition, the optical fibers may be attached to a support, in particular in the form of a tape. Specifically, the support is made of polyimide (PI) or polyethylene terephthalate (PET). In particular, the support has the same width as the width of the fibers placed side by side. This reduces the likelihood of the tape 145 bending. The support may be located on the upper or lower surface of the optical fibers, or it may be encapsulated around the fibers. Preferably, the support is located at least on the lower surface of the optical fibers, again to limit their degradation during successive rotations.

[0060] Optical fibers can be of any type, including silica or organic materials. The number of fibers, particularly per strip 145, can be of any size, including 6, 12, or 24 fibers.

Claims

Demands

1. A data transmission device (10) comprising - at least two concentric drums (101, 102, 103) freely rotating about an axis of rotation (Ar), and - at least two wired communication elements (104), each drum (101, 102, 103) comprising a set of walls (110, 120, 130) forming in common two pairs at least two concentric compartments (106) such that each compartment (106) comprises an inner side wall (160) formed by one of the drums (101, 102, 103) and an outer side wall (161) formed by the other drum(s) (101, 102, 103), each wired data transmission element (104) being disposed in one of the compartments (106), each wired communication element (104) comprising a movable part (140) arranged between a first fixed part (141) and a second fixed part (142),the first fixed part (141) being (143) fixed to the internal wall (160) of one of the dwellings (106) and the second fixed part (142) being fixed to the external wall (161) of said dwelling (106).

2. Transmission device according to claim 1, comprising at least three concentric drums (101, 102, 103).

3. Transmission device according to claim 2, wherein at least two of the housings (106) comprise a common side wall (165), wherein at least two wired communication members (104) each comprise one of their fixed parts (141, 142) fixed to said or one of said common walls (165), and wherein said fixed parts (141, 142) fixed to said or one of said common walls (165) are connected to each other by a linking member (150).

4. Transmission device according to any one of claims 1 to 3, wherein the wired communication means (104) comprise at least one optical fiber assembly and / or at least one copper cable assembly.

5. A transmission device according to claim 4, wherein the wired communication means (104) comprise at least one optical fiber assembly, the moving portion of which (140) is in the form of at least one strip (145) comprising a first surface and a second surface opposite each other, the first surface

6.

7.

8.

9.

10. (145) being free and the second surface being in contact with the inner wall (160) and the outer wall (161) of one of the housings (106). Transmission device according to claim 5, wherein said at least one strip of optical fibers (145) has reversible elastic properties. Transmission device according to claim 5 or 6, wherein the optical fibers of said at least one band (145) are glued together. Transmission device according to any one of claims 5 to 7, wherein said at least one band (145) comprises a support on which the optical fibers are glued. Transmission device according to any one of claims 5 to 8, wherein said at least one strip of optical fibers (145) is pressed against the inner wall (160) and the outer wall (161) of one of the housings (106). Optronic recognition and surveillance systems (30) comprising a data transmission device (10) according to any one of claims 1 to 9.

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