Method and device for locating an optical fiber

Abstract

The present invention relates to a method and device for locating an optical fiber (FBR) embedded in a volume. In particular, the method comprises at least: determining a position of the optical fiber (POS_FBR) as a function of at least one detection level (DET_LVL) of a radiation source (SRC) for at least one source position (POS_SRC) provided by a detection device (DXS) connected to the optical fiber (FBR). Figure for the abstract: Fig. 1

Description

Title of the invention: Method and device for locating an optical fiber Technical field

[0001] The present invention relates to the field of locating optical fiber networks. More particularly, the present invention relates to a method and a device for locating an optical fiber, as well as an associated system and computer program. Prior art

[0002] The invention relates to the context of locating buried optical fibers, such as optical fibers buried in the ground of a building or a street. In fact, there are significant differences between the location information entered during the installation of an optical fiber and its actual position. These differences often reach several tens of centimeters. However, it is essential to be able to precisely locate a buried optical fiber, in particular to avoid damaging it during work, or to add an optical connection point, or to repair it.

[0003] Unlike an electrical cable, an optical fiber buried in the ground cannot be detected by analyzing the electromagnetic field at the ground surface. This is why a known solution for locating a buried optical fiber consists of inserting a metal needle into the sheath containing the optical fiber, then detecting this needle by electromagnetic means. The needle is supplied with an electrical voltage at a given frequency, which allows it to be located on the surface using an electromagnetic detector. However, this solution has a number of disadvantages, including the following.

[0004] On the one hand, the sheath of the optical fiber may be obstructed, or occupied by other cables, or even have bends. In which case, it is simply not possible to insert a metal needle into the sheath of the optical fiber to locate it. On the other hand, the location accuracy of existing solutions is not fully satisfactory. Electromagnetic noise from various sources, such as interference with nearby electrical networks or thermal noise, disrupts the location measurements of the metal needle and degrades the location accuracy of the optical fiber.

[0005] There is therefore a need for a solution enabling a buried optical fiber to be precisely located, and this in a non-invasive manner (i.e. without having to dig into the ground). Statement of the invention

[0006] The present invention aims to remedy all or part of the drawbacks of the prior art, in particular those set out above.

[0007] For this purpose, and according to one aspect of the invention, a method is proposed for locating an optical fiber buried in a volume, the method comprising at least: - determining a position of the optical fiber as a function of at least one detection level of a radiation source for at least one position of the source provided by a detection device connected to the optical fiber.

[0008] The proposed solution makes it possible to precisely locate an optical fiber buried in a volume (e.g. a floor or a wall), and this in a non-invasive manner.

[0009] In particular, the proposed solution exploits the property that an optical fiber can detect a mechanical or acoustic wave propagating in the ground. The radiation source (e.g. a loudspeaker, or a percussion device, or a blowtorch) is located at the surface of the ground or in the vicinity of this surface. It generates, for example, acoustic or mechanical vibrations. These vibrations propagate in the form of waves in the ground and induce deformations (elongations or compressions) of the optical fiber.

[0010] The detection device is connected to one end of the optical fiber to be located, and uses the optical fiber as a sensor to detect the vibration source. This includes a distributed acoustic detection device or a distributed vibration detection device. This device sends light pulses into the optical fiber and measures the characteristics of the reflected light, and makes it possible to measure the deformations of the optical fiber induced by the vibrations. In fact, acoustic or vibration disturbances induce deformations of the optical fiber, which modifies the characteristics of the reflected light (e.g. its amplitude, its phase).

[0011] The detection device thus provides a detection level of the vibration source. This detection level is a function of the distance between the source and the optical fiber. The closer the vibration source is to the fiber, the greater the deformations of the fiber induced by the vibrations, and the higher the detection level of the source.

[0012] By using the detection level(s) obtained for different positions of the vibration source, the proposed solution makes it possible to estimate a position of a point of the optical fiber relative to the ground surface. It thus makes it possible to locate the path of the fiber in the ground.

[0013] We have described above the operation of the proposed solution with reference to a vibration source. It should be noted that the proposed solution operates in similarly in the case of a heat source. The heat source causes thermal conduction in the ground, which also induces deformation of the optical fiber and can be detected by the detection device.

[0014] In particular embodiments, the localization method may further comprise one or more of the following characteristics, taken in isolation or in all technically possible combinations.

[0015] According to one embodiment, a detection level of the source is obtained for each of a plurality of positions of the source, and the position of the optical fiber is estimated based on the detection levels obtained.

[0016] This embodiment contributes to precisely locating the optical fiber. The position of the optical fiber is here estimated using a plurality of detection levels of the source respectively obtained for different positions of the latter. The source can thus be moved from near to far to obtain different detection levels, and deduce a position of the optical fiber.

[0017] According to one embodiment, said estimated position of the optical fiber corresponds to the position of the source for which the detection level obtained is maximum among several positions of the source located in a search zone.

[0018] According to this embodiment, the determination of a position of the optical fiber is implemented in a given search area, and several detection levels are respectively obtained for different positions of the source within this search area. The source is, for example, moved by a user to reach a maximum detection level, which gives the estimated position of the fiber. This embodiment thus makes it possible to precisely locate the optical fiber, and has minimal implementation complexity.

[0019] According to one embodiment, the method comprises several determinations of a position of the optical fiber respectively implemented for different search zones, a said position of the optical fiber being determined as a function of at least one detection level obtained for at least one position of the source included in a said search zone.

[0020] This embodiment makes it possible to determine the path of the optical fiber. Indeed, several positions of the optical fiber are determined for different search areas according to this embodiment. Several fiber location points are thus obtained, making it possible to characterize the path of the fiber in the ground.

[0021] According to one embodiment, the method comprises: - provide a map (e.g. a graphic representation) representative of at least one determined position of the optical fiber.

[0022] This embodiment is particularly advantageous in that it makes it possible to restore the location of the optical fiber to a user.

[0023] According to one embodiment, the map provided is furthermore representative of at least one theoretical (i.e. expected) position of the optical fiber.

[0024] This embodiment allows a user to view the location of the optical fiber planned during its installation and the actual location of the optical fiber, and thus to see the differences between the two. Indeed, the map provided represents not only the determined positions of the fiber but also the theoretical positions thereof, that is to say the location information entered during the installation of the optical fiber.

[0025] According to one embodiment, the provision of the card comprises at least one step among the following: - interpolate determined positions of the optical fiber; and - regress determined positions of the optical fiber.

[0026] It is proposed in this embodiment to carry out an interpolation or a regression of several determined positions of the optical fiber, which advantageously makes it possible to generate an optical fiber trace. This embodiment makes it possible to restore to a user the trace of the optical fiber and allows him to visualize the path of the fiber.

[0027] According to this embodiment, the interpolation or regression of the determined positions of the optical fiber is carried out as a function of a minimum radius of curvature of the optical fiber.

[0028] This embodiment is advantageous in that it makes it possible to obtain a reliable fiber layout from a few determined positions of the fiber. Correlatively, it makes it possible to reduce the necessary number of positions of the optical fiber to obtain a reliable layout. To ensure the proper functioning of the optical fiber, it is installed while respecting a minimum bending radius (depending on the type of optical fiber). This embodiment proposes to use this minimum bending radius to generate the layout of the optical fiber.

[0029] According to one embodiment, a determination of a position of the optical fiber comprises: obtaining a depth of the optical fiber relative to a surface of the volume, this depth being determined as a function of a said detection level.

[0030] This embodiment makes it possible to locate the optical fiber in three dimensions. The fiber is here located not only in the ground plane, but also in depth. The detection level of the source makes it possible to estimate the depth of the optical fiber, for example by using reference models (e.g. a model of propagation of acoustic waves in the ground) or reference data (e.g. detection levels obtained for different depths of a fiber in a ground).

[0031] According to one embodiment, a said detection level of the source is determined using at least one neural network.

[0032] The use of one or more neural networks makes it possible to determine a detection level of the source from optical measurements made at the output of the fiber by the detection device. The neural network(s) are trained to optimize the reliability of the detection of a radiation source. This embodiment thus makes it possible to obtain reliable detection levels of the source, and therefore contributes to precisely locating the optical fiber.

[0033] According to one embodiment, said at least one determination of a position of the optical fiber is implemented by a location device and comprises: - sending to the source an instruction to generate vibrations and / or heat; and / or - send an instruction to the detection device to measure a detection level.

[0034] This embodiment makes it possible to automate the location of the optical fiber, and to limit the interventions required by a user (e.g. a technician). The location of the optical fiber is here carried out by a location device (e.g. a user terminal, or an augmented reality device). The latter controls the source and the detection device. These different devices being controlled automatically, this embodiment allows a particularly precise location of the optical fiber.

[0035] According to one embodiment, said at least one determination of a position of the optical fiber is implemented by a user terminal, and a said position of the source is obtained by locating the user terminal.

[0036] This embodiment is particularly advantageous in that it allows a user to locate a buried optical fiber using only his terminal and the detection device. Indeed, the location of the optical fiber is carried out by the user terminal (e.g. a mobile phone, or a tablet). It is further considered that the radiation source is located at (or near) the user terminal. It is for example the terminal which generates acoustic vibrations with its loudspeaker, or the user (e.g. a technician) equipped with the terminal who generates mechanical vibrations by striking the ground with a tool.

[0037] According to one embodiment, said at least one determination of a position of the optical fiber is implemented by a so-called augmented reality device. In addition, the augmented reality device determines a said position of the source and indicates this position to a user.

[0038] This embodiment makes it easier for a user to locate an optical fiber. The location of the optical fiber is here carried out by an augmented reality device (e.g., augmented reality glasses). This device interactively guides a user to locate the fiber by indicating where the fiber should be positioned. source.

[0039] According to one aspect of the invention, there is provided a device for locating an optical fiber buried in a volume, the device comprising an optical fiber locator configured to determine at least one position of the optical fiber as a function of at least one detection level of a radiation source for at least one position of the source provided by a detection device connected to the optical fiber.

[0040] The proposed location device may be configured to implement any of the embodiments of a method according to the invention. In particular, for each step or operation of a method according to the invention, the location device may comprise a device or module configured to implement this step or operation.

[0041] According to one embodiment, the location device is (included in, implemented by) one of: a user terminal, and a so-called augmented reality device.

[0042] According to one embodiment, the augmented reality device comprises an indicator configured to indicate to a user a position of the source.

[0043] According to one embodiment, the radiation source is a vibration and / or heat source.

[0044] According to one aspect of the invention, there is provided a system for locating an optical fiber buried in a volume, the system comprising: - a detection device intended to be connected to the optical fiber and configured to provide at least one level of detection of a radiation source; and - an optical fiber locator configured to determine at least one position of the optical fiber based on said at least one detection level.

[0045] According to one embodiment, the system comprises the radiation source, the source being controlled by the locating device.

[0046] According to one aspect of the invention, there is provided a computer program (or a set of computer programs) comprising instructions for implementing the steps of a method according to the invention, when the computer program is executed by at least one processor or computer.

[0047] The computer program may be formed of one or more sub-parts stored in the same memory or in separate memories. The program may use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0048] According to one aspect of the invention, there is provided a computer-readable information medium diner comprising a computer program in accordance with the invention.

[0049] The information carrier may be any entity or device capable of storing the program. For example, the carrier may comprise a storage means, such as a non-volatile memory or ROM, for example a CD-ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a floppy disk or a hard disk. Furthermore, the storage medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by a telecommunications network or by a computer network or by other means. The program according to the invention may in particular be downloaded onto a computer network. Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

[0050] The proposed device, system, computer program and information medium have the advantages described above in connection with the proposed localization method. Brief description of the drawings

[0051] Other characteristics and advantages of the present invention will emerge from the description provided below, illustrating embodiments of the invention given by way of example and without any limiting character, with reference to the attached drawings:

[0052] [Fig.l] represents a system for locating an optical fiber according to an embodiment of the invention;

[0053] [Fig.2] represents steps of a method for locating an optical fiber according to an embodiment of the invention;

[0054] [Fig. 3] represents an example of a search zone of an optical fiber and of detection levels, used by a location system according to an embodiment of the invention;

[0055] [Fig.4] represents an example of search zones of an optical fiber, used by a location system according to an embodiment of the invention;

[0056] [Fig.5] represents an example of a map provided by a device for locating an optical fiber according to an embodiment of the invention;

[0057] [Fig.6] represents the architecture of a system for locating an optical fiber according to one embodiment of the invention; and

[0058] [Fig.7], [Fig.8], and [Fig.9] represent a system for locating an optical fiber according to embodiments of the invention. Description of the embodiments

[0059] The present invention applies, in particular, to the implementation of systems for locating buried optical fibers. The description of the invention below refers to an optical fiber buried in a ground. However, the invention also applies to the location of a fiber buried in a wall, a ceiling, or any other volume.

[0060] [Fig.l] represents a system for locating an optical fiber according to an embodiment of the invention. This figure is described below to introduce the present invention and to exemplify an embodiment.

[0061] The location system SYS comprises, according to this embodiment: a location device APP, a radiation source SRC, a detection device DXS, and a geographic information system GIS.

[0062] The proposed SYS system makes it possible to locate the underground optical fiber FBR. As illustrated in [Fig.l], the optical fiber FBR is partly buried in a ground. This can, for example, be the ground of a building or a street.

[0063] The geographic information system GIS is configured to provide the location device APP with one or more theoretical positions POS_SIG of the FBR optical fiber. These theoretical positions correspond to the location information entered during the installation of the FBR optical fiber. As mentioned previously, there may be significant differences between the location information entered during the installation of an optical fiber and the actual position thereof.

[0064] This location information can be used by the APP location device to determine the areas in which the FBR optical fiber should be searched, which we detail with reference to [Fig.4]. The theoretical positions POS_SIG of the FBR fiber can also be indicated to a user by the APP device.

[0065] The SRC radiation source is located at or near the ground surface. It is intended to be detected by the DXS detection device which uses the FBR optical fiber as a sensor.

[0066] The SRC radiation source is, according to one embodiment, a vibration and / or heat source. The vibration may be mechanical and / or sound, etc. By “sound source”, we mean a source configured to emit a sound among all types of sounds: from infrasound to ultrasound to audible sounds.

[0067] In particular, the SRC source is configured to generate acoustic and / or mechanical vibrations, and / or heat. We also use hereinafter the expression “stimulus source” to designate the SRC source and refer to any type of stimuli, and in particular acoustic and mechanical vibrations, and heat.

[0068] The SRC source may be, for example, a loudspeaker generating acoustic vibrations, or a percussion device generating mechanical vibrations. The vi- Acoustic or mechanical waves propagate in the form of waves in the ground and cause DEF deformations of the FBR optical fiber (deformations accentuated in this figure for illustrative purposes). The same is true when the SRC source is a heat source such as a blowtorch. The SRC heat source causes thermal conduction in the ground, which induces a DEF deformation of the FBR optical fiber.

[0069] This SRC source can in particular be controlled by the CMD_SRC commands sent by the APP location device. It can also be configured to provide its position POS_SRC to the APP device. Other embodiments are presented with reference to Figures 7 and 8, in which the SRC source is not controlled by the APP device but rather by a user (e.g. a technician). It can, for example, be hammer blows made by a user on the surface of the ground. Thus, the stimuli can be generated manually (e.g. by a technician), or by an automatic source of stimuli.

[0070] Embodiments could also be envisaged in which the SRC source is capable of producing stimuli of different natures: acoustic vibrations, mechanical vibrations, and / or heat. The type of stimuli generated by the SRC source could thus be selected according to the nature of the ground. This makes it possible to improve the detection of the SRC source by the DXS detection device, and therefore contributes to precisely locating the FBR optical fiber.

[0071] Furthermore, according to one embodiment, the SRC source generates stimuli using a code sequence (e.g. a reference sequence). For example, the SRC source may use a code sequence comprising a series of long and short stimuli. Such a code sequence is known in particular to the DXS detection device, which makes it possible to improve the detection of the SRC source. Indeed, in a noisy environment (e.g. a road with vibrations generated by vehicles or nearby works), the use of a code sequence makes it easier to distinguish the stimuli generated by the SRC source from noise or other disturbances. This thus makes it possible to improve the detection of the SRC source, and contributes to precisely locating the FBR optical fiber.

[0072] The DXS detection device is connected to one end of the FBR optical fiber (e.g. at an optical branch point). It uses the FBR optical fiber as a continuous sensor to detect the SRC source.

[0073] The DXS detection device may be a distributed acoustic sensing device, or a distributed vibration sensing device. It could also be a distributed temperature sensing device. These devices use in particular optical time domain reflectometry techniques.

[0074] The DXS device sends light pulses into the FBR optical fiber and performs optical measurements at the output of the fiber. By thus measuring the characteristics of the reflected light (e.g. amplitude, phase, or other optical parameters), the DXS device can detect the DEF deformations of the FBR optical fiber induced by the SRC source.

[0075] The DXS detection device is thus configured to provide a detection level DET_LVL of the SRC source for a given position POS_SRC thereof. This detection level DEL_LVL characterizes a deformation level DEF of the FBR fiber, and therefore characterizes the distance between the SRC source and the FBR optical fiber. The closer the SRC source is to the FBR fiber, the greater the induced deformations DEF, and the higher the detection level DET_LVL.

[0076] According to one embodiment, this DXS device uses at least one neural network taking as input optical measurements made at the output of the fiber, and providing as output a source detection level DET_LVL. Such a neural network can be trained using simulated data (i.e. computer-generated), and / or field data.

[0077] More particularly, the DXS device can use a plurality of neural networks respectively dedicated to the detection of a particular type of stimuli. It can thus select the neural network used according to the type of stimuli generated by the SRC source.

[0078] As illustrated in [Fig.l], the DXS detection device can provide a distance DET_DIST at which the SRC source is detected, i.e. the fiber length between the deformation DEF and the DXS detection device. This device can also provide a depth DPT of the FBR optical fiber at the deformation DEF (i.e. at the location where the SRC source is detected). The fiber depth is defined relative to the ground surface.

[0079] According to the embodiment of [Fig.l], the DXS detection device is controlled by the APP device. For example, the APP device sends a CMD_DXS command comprising an instruction to measure a DET_LVL detection level. Alternatively, the DXS device could operate autonomously and regularly provide DET_LVL detection levels to the APP device.

[0080] The APP location device is configured to determine at least one position of the FBR optical fiber. In particular, it estimates the position of the FBR optical fiber using the DET_LVL detection levels provided by the DXS device.

[0081] The APP device may in particular implement an application intended for a user (e.g. a technician) to enable him to locate the FBR optical fiber. For example, the APP location device may be a user terminal (e.g. a mobile phone, or smartphone), or an augmented reality device (e.g. augmented reality glasses).

[0082] By augmented reality device, it is meant here a device configured to integrate virtual elements (generated by computer) into a real environment on a display device. Note that a user terminal (e.g. a smartphone) can also implement augmented reality techniques.

[0083] The APP device may comprise a display device DISP for indicating to a user: the detection levels DET_LVL provided by the detection device DXS, the theoretical positions of the fiber POS_SIG, and / or the positions of the fiber FBR determined by the APP device. This APP device may also implement the source of stimuli SRC, which is presented with reference to [Fig.8].

[0084] We detail below the operation of the APP location device with reference to figures 2 to 5, and its hardware architecture with reference to [Fig.6].

[0085] [Fig.2] represents steps of a method for locating an optical fiber according to an embodiment of the invention. This figure presents the operation of the APP locating device previously introduced.

[0086] According to the embodiment illustrated by [Fig.2], the proposed method comprises all or part of the steps S100 to S300 described below and implemented by the APP device.

[0087] In step S100, the APP device obtains one or more theoretical positions POS_SIG of the FBR optical fiber (i.e. expected or captured positions). In particular, it receives this location information from the geographic information system GIS.

[0088] In step S200, the APP device determines at least one position of the optical fiber POS_FBR in a given search area.

[0089] The APP device can carry out several iterations of step S200 for different search areas. It thus determines a plurality of positions of the fiber POS_FBR. We detail this point with reference to [Fig.4].

[0090] To determine a position of the fiber POS_FBR in a given search zone, and according to the embodiment of [Fig.2], step S200 comprises all or part of steps S210 to S250 described below.

[0091] In step S210, the APP device obtains a position POS_SRC of the source of SRC stimuli. This position POS_SRC can be defined relative to the ground surface, or absolutely relative to the terrestrial reference frame (e.g. geographical coordinates provided by a positioning device of a terminal).

[0092] The position of the POS_SRC source can be obtained in different ways. It can be provided to the APP device by the SRC source itself, as illustrated in [Fig.l]. Alternatively, the POS_SRC position can correspond to the position of the terminal APP user implementing the location of the FBR fiber. This POS_SRC position can also be determined by the APP device, then indicated to a user (e.g. technician) who will generate vibrations at the indicated position. These different embodiments are described with reference to Figures 7 to 9.

[0093] In step S220, the APP device controls the SRC source and / or the DXS detection device. It sends to the SRC source a CMD_SRC command comprising a stimulus generation instruction, and / or sends to the DXS detection device a CMD_DXS command comprising an instruction to measure a detection level of the DET_LVL source.

[0094] Alternatively, the SRC source and the DXS detection device could operate autonomously, or be controlled by a user.

[0095] In step S230, the APP device obtains a detection level DET_LVL from the source SRC. This detection level is provided by the detection device DXS and is associated with the position of the source POS_SRC.

[0096] The APP device can indicate to a user the detection level DET_LVL obtained for this position of the source POS_SRC (eg via an application on a terminal).

[0097] In step S240, the APP device determines whether a stopping criterion STP_CRT is verified. If so, the method continues to step S250. Otherwise, the method repeats steps S210-S230 so as to obtain an additional detection level DET_LVL for a different position of the source POS_SRC.

[0098] This stopping criterion STP_CRT corresponds, according to one embodiment, to the fact that a maximum detection level of the source DET_LVL has been detected by the APP device and / or reported by a user. The APP device can also indicate to the user that a maximum detection level DET_LVL has been detected (e.g. via an application on a terminal).

[0099] If a maximum has not been detected or reported, the APP device repeats steps S210-S230 to obtain a detection level DET_LVL associated with another position of the source POS_SRC. The SRC stimuli source can thus be moved from one location to another to reach a maximum detection level of the SRC source. We present an example of searching for the maximum detection level with reference to [Fig.3].

[0100] In the context of the invention, it could be envisaged to use other stopping criteria. For example, a stopping criterion could correspond to obtaining a sufficient number of measurements, i.e. a number of detection levels associated with different positions of the source greater than a threshold.

[0101] In step S250, the APP device estimates a position of the fiber POS_FBR based on the obtained detection levels DET_LVL and the positions of the source associated POS_SRC.

[0102] This estimated position POS_FBR is a planar position. It characterizes the location of a point of the FBR fiber in a plane substantially parallel to the ground (the xy plane in the figures). It can be defined relatively to the ground surface, or absolutely to the terrestrial reference frame (e.g. geographic coordinates).

[0103] In particular, the estimated position of the fiber POS_FBR corresponds (is associated) with the position of the source SRC for which the obtained detection level DET_LVL is maximum, among the different positions of the source POS_SRC in the search area considered. In other words, the APP device associates a position of a point of the searched fiber FBR with the position of the source POS_SRC for which a maximum detection level is detected and / or signaled.

[0104] In the context of the invention, other embodiments could also be envisaged. The position of the optical fiber POS_FBR could be estimated by using an interpolation of the detection levels, then selecting the position for which the interpolated detection level is maximum. The APP device can also use the other information provided by the DXS detection device, such as the distance DET_DIST, to estimate the position of the FBR fiber.

[0105] Furthermore, we have described here the proposed solution by considering a plurality of detection levels DET_LVL associated with different positions of the source POS_SRC. It is however possible to obtain an estimate of the position of the fiber POS_FBR from a single detection level DET_LVL and the position of the associated source POS_SRC, for example by using reference models, or reference data, or other information provided by the DXS detection device.

[0106] According to one embodiment, the APP device obtains in step S250 a depth of the DPT fiber relative to the ground surface. The FBR optical fiber is thus located in three dimensions. This DPT depth is determined either by the DXS detection device or by the APP device itself.

[0107] More precisely, the depth DPT is determined based on the maximum detection level obtained, i.e. the detection level obtained at the position of the source POS_SRC associated with the estimated position of the fiber POS_FBR. The depth of the optical fiber DPT can be determined from a detection level DET_LVL using reference models (e.g. a model of propagation of acoustic waves in the ground), or reference data (e.g. detection levels obtained for different depths of the fiber in a ground).

[0108] In step S300, the APP device provides a map MAP representative of at least one determined position of the fiber POS_FBR. This map MAP corresponds to a re graphic presentation on which the FBR optical fiber is located. We present this MAP map in more detail with reference to [Fig.5].

[0109] In particular, the APP device resituates this map MAP to a user via a display device DISP. Alternatively, this map MAP and / or the determined positions POS_FBR could be communicated by the APP device to another device to be stored or displayed.

[0110] The proposed method thus makes it possible to precisely locate a buried optical fiber, and to do so in a non-invasive manner. It should be noted that the order in which the steps described above are carried out constitutes only an example of an embodiment, other variants being possible.

[0111] The proposed method comprises all or part of the steps implemented by the APP location device. Furthermore, the proposed method may comprise the steps implemented by the DXS detection device and / or the SRC source.

[0112] [Fig. 3] represents an example of a search area of ​​an optical fiber and detection levels, used by a location system according to an embodiment of the invention. This figure is presented to exemplify the implementation of step S200, during which the APP device determines a position of the fiber POS_FBR in a search area.

[0113] This figure represents a top view of a ZI search area. The POS_SIG location information entered during the installation of the FBR fiber is indicated in dotted lines, while the actual location of the FBR fiber is represented in solid lines.

[0114] As mentioned previously, and according to one embodiment, the APP device obtains several detection levels DET_LVL associated with different positions of the source POS_SRC (eg by carrying out several iterations of steps S210-230). It then uses these detection levels DET_LVL to locate the optical fiber FBR.

[0115] Consider the example of [Fig.3]. A user of the APP device moves the SRC stimuli source (along the y axis) and seeks to maximize the detection level DET_LVL provided by the DXS detection device. The APP device thus obtains the detection levels DL1-DL4 respectively associated with the positions of the source SP1-SP4. The APP device then associates the position of the source SP3, for which the maximum detection level MAX_DET was obtained, with a position of the fiber POS_FBR.

[0116] We have described here a particular example of searching for the maximum detection level. Obviously, other search strategies could be envisaged. For example, the source of SRC stimuli could be moved using a cross or spiral search method, or by squaring the search area ZI.

[0117] It should also be noted that the APP device can guide the user in finding the maximum detection level by indicating the detection level DET_LVL provided by the DXS device. It can further indicate to the user that a maximum level MAX_DET has been detected.

[0118] [Fig.4] represents an example of search zones of an optical fiber, used by a location system according to an embodiment of the invention.

[0119] We describe this figure to exemplify the implementation of several iterations of step S200, during which the APP device determines several positions of the POS_FBR fiber in different search areas. The description given below constitutes only an example of an embodiment of the invention, other search strategies can be used to locate an FBR optical fiber.

[0120] This figure represents a geographical area LOC (eg a room of a building) seen from above. The FBR optical fiber is buried in the ground of this LOC area, and the SYS location system is used to locate it.

[0121] The APP device selects a first search zone ZI around a theoretical position T1 of the optical fiber FBR. The theoretical position T1 is obtained from the location information POS_SIG entered during installation. The APP device implements step S200 described above for this first search zone Z1, and thus determines a first position PI of the optical fiber. Then, the APP device selects a second search zone Z2 centered around another theoretical position T2 of the fiber. It then determines a second position P2 of the optical fiber in this search zone Z2 by implementing step S200.

[0122] By repeating step S200 for different search areas within a geographical area LOC, the APP device makes it possible to locate the FBR optical fiber and to precisely determine its path in the ground. It then provides the user with a map MAP representative of the determined positions of the POS_FBR fiber, which we detail with reference to the following figure.

[0123] [Fig.5] represents an example of a map provided by a device for locating an optical fiber according to an embodiment of the invention. This figure illustrates an example of a map MAP provided in step S300 by the locating device APP.

[0124] As mentioned previously, the APP device can display the map MAP representative of the determined positions of the FBR fiber using a display device DISP (eg the screen of a user terminal, or augmented reality glasses).

[0125] According to one embodiment, the MAP map provided by the APP device indicates the different determined positions of the FBR fiber, i.e. location points of the optical fiber. [Fig.5] illustrates location points P1-P4 of the FBR optical fiber. It could also be envisaged that the MAP map indicates a or several theoretical positions POS_SIG of the FBR optical fiber.

[0126] According to one embodiment, the MAP map provided by the APP device comprises a trace of the TRJ fiber obtained from the determined positions P1-P4. This allows a user to visualize the path of the FBR optical fiber in the ground. The MAP map can indicate either the location points of the fiber P1-P4, or the trace of the TRJ fiber, or even both at the same time. This latter case is illustrated by [Fig.5].

[0127] According to this embodiment, the APP device generates the trace of the TRJ fiber from the determined positions POS_FBR. It thus implements a step of interpolation or regression of the determined positions of the optical fiber POS_FBR.

[0128] The APP device can use any interpolation or regression technique to generate the TRJ plot. We can cite, for example, linear or polynomial interpolation techniques, or even spline interpolations. Also, the APP device could use a linear or non-linear regression, or even a machine learning algorithm (e.g. an artificial neural network) to generate the TRJ plot.

[0129] Note that in the case of interpolation, the TRJ fiber path passes through the determined POS_FBR positions, as illustrated in [Fig.5]. In the case of regression, the TRJ fiber path may not pass through the determined POS_FBR positions and only approach them.

[0130] In addition, the APP device can use a minimum bending radius of the optical fiber to generate the TRJ fiber path. Depending on the type of the FBR optical fiber, it is installed while respecting a certain minimum bending radius. If the FBR optical fiber has a bend whose bending radius is less than this minimum, the operation of the optical fiber is not ensured, and it could be damaged. It is therefore proposed here to use this minimum bending radius to generate the TRJ fiber path, that is to say that the generated TRJ path respects this bending constraint of the FBR fiber.

[0131] We have described above the operation of the APP location device. We now describe its hardware architecture with reference to the following figure.

[0132] [Fig.6] represents the architecture of a system for locating an optical fiber according to one embodiment of the invention.

[0133] The SYS location system comprises all or part of the following elements: the APP location device, the SIG system, the DXS detection device, and the SRC source.

[0134] The location device APP comprises, according to the embodiment of [Fig.6], at least one processor PROC, and at least one memory MEM.

[0135] More particularly, the APP device has, according to one embodiment, the hardware architecture of a computer. The memory MEM constitutes an information medium in accordance with the invention, i.e. readable by the processor PROC and on which is recorded a computer program PROG in accordance with the invention. The program PROG comprises instructions for carrying out steps of a location method in accordance with the invention, when the program PROG is executed by the processor PROC. The program PROG defines in particular the functional modules of the device APP, which control the hardware elements of the latter.

[0136] The APP device may also comprise a display device DISP. The display device DISP may, for example, be used to render the map MAP to a user. It could also be used to signal to a user the detection levels DET_LVL provided by the detection device DXS.

[0137] As illustrated in [Fig.6], the APP device comprises a communication device COM communication configured to communicate with the DXS detection device, and / or the SRC source, and / or the GIS system. No limitation is attached to the nature of the communication interfaces between these devices, which may be wired or wireless, and may implement any protocol known to those skilled in the art.

[0138] Generally, for each step (or operation) of a method for locating an optical fiber according to the invention, the APP device may comprise a corresponding element configured to carry out said step.

[0139] In particular, according to one embodiment, the APP location device comprises at least one of the following elements: - a detection level obtainer of a source (eg a receiver) configured to obtain at least one detection level DET_LVL of the source SRC for a position of the source POS_SRC and provided by the detection device DXS connected to the FBR fiber; and - an optical fiber position estimator configured to estimate at least one position of the optical fiber POS_FBR based on said at least one obtained detection level DET_LVL.

[0140] We have previously presented a particular embodiment of the proposed localization system, notably illustrated by [Fig.l]. We present other embodiments of this system SYS with reference to the following figures.

[0141] [Fig.7], [Fig.8] and [Fig.9] represent a system for locating an optical fiber according to embodiments of the invention.

[0142] These figures illustrate several embodiments of the SYS location system by way of example. The SYS system may further comprise one or more of the following features, taken individually or in any technically possible combination.

[0143] [Fig.7] illustrates an embodiment in which the APP device is implemented implemented by augmented reality glasses worn by a USR user (e.g. a technician). The source of SRC stimuli is here provided by the USR user who strikes the ground with a tool (e.g. a hammer). According to this embodiment, the APP device locates the buried FBR optical fiber by proceeding as follows.

[0144] The APP device determines a position POS_SRC of the vibration source SRC (step S210). It indicates this position to the user USR, who sees it appear in his field of vision. The user USR then strikes the ground with his tool at the indicated position. The APP device communicates with the detection device DXS to obtain the source detection level DET_LVL associated with this position POS_SRC (step S230).

[0145] The APP device repeats these steps to obtain several detection levels DET_LVL associated with different positions of the source POS_SRC. It then uses the detection levels obtained to determine a position of the optical fiber POS_FBR (step S250).

[0146] The use of augmented reality glasses is particularly advantageous in that it allows the USR user to be interactively guided to locate the FBR optical fiber.

[0147] [Fig.8] illustrates an embodiment in which the APP location device is implemented by a user's terminal USR (e.g. a smartphone, or a tablet). The APP device also provides the source of SRC stimuli, for example by using the terminal's speaker. We present below an example of operation of the APP location device according to this embodiment.

[0148] The user USR places the APP device on the ground surface (or in the vicinity of this surface). The APP device obtains the position POS_SRC of the SRC stimuli source by locating the APP device (step S210). To obtain this POS_SRC position, the APP device uses for example a GPS receiver, or any other positioning means. Then, the APP device activates the SRC stimuli source (step S220). It receives from the detection device DXS a detection level DET_LVL associated with the position of the POS_SRC source (step S230). The APP device can thus obtain several DET_LVL detection levels for different positions of the POS_SRC source, and deduce therefrom a position of the POS_FBR fiber (step S250).

[0149] This embodiment advantageously allows the USR user to locate the FBR optical fiber from only his APP terminal and the DXS detection device.

[0150] [Fig.9] illustrates an embodiment in which the APP location device is implemented by a user's terminal USR. According to this embodiment, the APP device controls a stimulus source SRC configured to generate vi- acoustic and / or mechanical signals, and / or heat. This figure illustrates a source of SRC stimuli implemented by a ground device (e.g. a robot), but an aerial device (e.g. a drone) could also be used.

[0151] The APP device may proceed in the following manner to locate the optical fiber FBR. First, the APP device obtains the position of the source POS_SRC (step S210). For example, the source device SRC moves autonomously and communicates its position POS_SRC to the APP device. Alternatively, the APP device controls the source device SRC to reach a given position POS_SRC.

[0152] Then, the APP device sends to the source device SRC a stimulus generation instruction (step S220). The APP device communicates with the detection device DXS to obtain a source detection level DET_LVL associated with this position POS_SRC (step S230). The APP device uses one or more detection levels DET_LVL thus obtained to determine the position of the fiber POS_FBR (step S250).

[0153] This embodiment makes it possible to automate the location of the optical fiber, and to limit the interventions required by the user (e.g. a technician). The various devices of the location system being controlled automatically, this embodiment allows particularly precise location of the optical fiber.

[0154] Additional Variants: A person skilled in the art will understand that the embodiments and variants described above constitute only non-limiting examples of implementation of the invention. In particular, a person skilled in the art may envisage any adaptation or combination of the embodiments and variants described above in order to meet a very specific need.

[0155] It should also be noted that the order in which the steps of a method according to the invention are carried out, in particular with reference to the attached drawings, constitutes only an exemplary embodiment without any limiting character, variants being possible. In particular, a method according to the invention may comprise one or more iterations of the steps described above, in particular with reference to the attached drawings. Furthermore, the reference signs do not limit the scope of the protection, their sole function being to facilitate the understanding of the claims.

Claims

Claims

1. Method for locating an optical fiber (FBR) buried in a volume, the method comprising at least: - determining (S200) a position of the optical fiber (POS_FBR) as a function of at least one detection level (DET_LVL) of a radiation source (SRC) for at least one position of the source (POS_SRC) provided by a detection device (DXS) connected to the optical fiber (FBR).

2. Method according to claim 1, wherein said estimated position of the optical fiber (POS_FBR) corresponds to the position of the source (SRC) for which the obtained detection level (DET_LVL) is maximum among several positions of the source (POS_SRC) located in a search zone (Zl).

3. Method according to claim 1 or 2, comprising several determinations (S200) of a position of the optical fiber (POS_FBR) respectively implemented for different search zones (Z1-Z2), a said position of the optical fiber (POS_FBR) being determined (S200) as a function of at least one detection level (DET_LVL) obtained for at least one position of the source (POS_SRC) included in a said search zone (Z1-Z2).

4. Method according to any one of claims 1 to 3, comprising: - providing (S300) a map (MAP) representative of at least one determined position of the optical fiber (POS_FBR).

5. Method according to claim 4, wherein the provision of the map (S300) comprises at least one of the following steps: - interpolating determined positions of the optical fiber (POS_FBR); and - regressing determined positions of the optical fiber (POS_FBR).

6. A method according to any one of claims 1 to 5, wherein a determination (S200) of a position of the optical fiber (POS_FBR) comprises: - obtain (S250) a depth of the optical fiber (DPT) relative to a surface of the volume, this depth (DPT) being determined as a function of a said detection level (DET_LVL).

7. A method according to any one of claims 1 to 6, wherein a said source detection level (DET_LVL) is determined using at least one neural network.

8. Method according to any one of claims 1 to 7, wherein said at least one determination (S200) of a position of the optical fiber (POS_FBR) is implemented by a location device (APP) and comprises: - sending (S220) to the source (SRC) an instruction for generating vibrations and / or heat (CMD_SRC); and / or - sending (S220) to the detection device (DXS) an instruction for measuring a detection level (CMD_DXS).

9. Device (APP) for locating an optical fiber (FBR) buried in a volume, the device (APP) comprising an optical fiber locator configured to determine (S200) at least one position of the optical fiber (POS_FBR) as a function of at least one detection level (DET_LVL) of a radiation source (SRC) for at least one position of the source (POS_SRC) provided by a detection device (DXS) connected to the optical fiber (FBR).

10. Device (APP) according to claim 9, characterized in that the location device (APP) is one of: a user terminal, and a so-called augmented reality device.

11. Device (APP) according to claim 10, characterized in that the augmented reality device (APP) comprises an indicator configured to indicate to a user (USR) a position of the source (POS_SRC).

12. Device (APP) according to any one of claims 9 to 11, wherein the radiation source (SRC) is a vibration and / or heat source.

13. System (SYS) for locating an optical fiber (FBR) buried in a volume, the system (SYS) comprising: - a detection device (DXS) intended to be connected to the optical fiber (FBR) and configured to provide at least one detection level (DET_LVL) of a radiation source (SRC); and - an optical fiber locator configured to determine (S200) at least one position of the optical fiber (POS_FBR) as a function of said at least one detection level (DET_LVL).

14. System (SYS) according to claim 13, comprising the radiation source (SRC), the source (SRC) being controlled by a locating device (APP) comprising the optical fiber locator.

15. Computer program (PROG) comprising instructions for implementing the steps of a method according to one of claims 1 to 8, when the computer program (PROG) is executed by at least one processor (PROC).

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