Embedded device for generating automated georeferencing maps of buried cable conduits or pipes

Abstract

A location data acquisition device (1) intended to be installed on a wheel trencher (2) adapted to create a trench in the ground and lay a conduit (5) for cables or pipes at the bottom of the trench, said device (1) comprising: A satellite geolocation unit (11); A cellular communication unit (12) for communicating with a base station capable of providing correction values ​​for the satellite geolocation data; A control unit (13) capable of receiving at least one correction value from said base station (40) and calculating a corrected geolocation data point based on said correction value; Recording means (15) for recording said corrected data. (Shorthand figure: Figure 2)

Description

Title of the invention: On-board device for generating an automated georeferencing map of buried cable or pipe ducts

[0001] The invention relates to an on-board device for generating an automated georeferencing map of buried cable or pipe ducts, an associated generation method and an assembly for implementing such a method.

[0002] In the field of civil engineering, it is well known to bury cables and pipes, whether for example electrical cables, optical fibers or water and gas pipes.

[0003] In practice, the conventional procedure is to first lay sheaths in trenches which are then closed, before inserting the cables or pipes into the sheaths.

[0004] This practice is frequently performed by a machine tool called a trencher, such as a wheel trencher or a chain trencher.

[0005] Since the ducts are generally buried in public spaces, for example along roads, it is essential to have a precise and detailed map of the installation of these ducts. This makes it possible in particular to limit the risks of accidental destruction during subsequent civil engineering work.

[0006] However, the current practice of detecting the network after installation, in a closed trench, is generally imprecise.

[0007] There is thus a need for a simple and precise solution for generating a detailed map of the position of buried cables.

[0008] To this end, a geolocation data acquisition device is proposed, intended to be installed on a trencher adapted to form a trench and place a cable or pipe sheath in said trench, said device comprising:

[0009] - A satellite geolocation device adapted to calculate geolocation data calibration from signals emitted by at least one constellation of artificial satellites;

[0010] - A cellular communication device adapted to communicate with a station basic capable of providing a correction value for geolocation data;

[0011] - A control unit adapted to receive from the geolocation device a plurality of geolocation data and for each geolocation data, the control unit being adapted to send said geolocation data via the cellular communication device to said base station; the control unit being further adapted to receive from said base station at least one correction value and to calculate corrected geolocation data based on said correction value; and

[0012] - Recording means for recording said corrected data.

[0013] Advantageously, the device further comprises an inertial unit, the recording means being further adapted to record the data acquired from said inertial unit associated with the corrected data.

[0014] Advantageously, the cellular communication device communicates with a base station adapted to provide satellite geolocation correction data by kinematics in real time. This makes it possible to obtain particularly precise geolocation data from the acquisition device.

[0015] The invention also relates to a slicer for making trenches intended to receive a sheath, said slicer comprising a slicing member, a sheath guide and comprising an upper structure, and an acquisition device as described previously, fixed to said upper structure.

[0016] The invention also relates to a post-processing device comprising means for receiving the data recorded on an acquisition device of a trencher as described above; and a calculation unit adapted to calculate another correction of each corrected data item received from said acquisition device as a function of parameters comprising a value of installation height of the device relative to the bottom of the trench, a value of longitudinal offset between said device, a point of deposit of the sheath at the bottom of the trench, a value of diameter of said sheath, and data relating to a height of a sand bed in said trench, all of the data corrected by said post-processing device forming a map of buried cables of sheaths and / or pipes laid by said trencher on which said acquisition device is installed.

[0017] Advantageously, the post-processing device is adapted to calculate another correction of said corrected data acquired as a function of the data acquired by the inertial unit.

[0018] Advantageously, the post-processing device is adapted to associate with the recorded corrected data information relating to the nature of the cable intended to be inserted into the sheath and / or administrative location information of the installation location.

[0019] In particular when the acquisition device has not been able to calculate corrected data for acquired geolocation data, such as during a connection failure with said base station, said post-processing device is adapted to calculate said corrected data as a function of the data recorded by said acquisition device and as a function of a separately acquired correction value.

[0020] The invention also relates to an assembly for establishing a map of buried cables of ducts and / or pipes comprising a slicer as described previously and a post-processing device as described previously, said acquisition device of said slicer being adapted to communicate with said post-processing device via a communication member.

[0021] The invention also relates to a method for acquiring location data for a location data acquisition device intended to be installed on a trencher adapted to form a trench and place a cable or pipe sheath in said trench, said method comprising:

[0022] A step of acquiring geolocation data from signals emitted by at least one constellation of artificial satellites;

[0023] For each geolocation data, a step of acquiring a correction value of said geolocation data via a base station;

[0024] For each geolocation data, a step of calculating a corrected geolocation data as a function of said correction value; and

[0025] A step of recording said corrected data.

[0026] Other features and advantages of the invention will emerge from reading the description given below of a particular embodiment of the invention, given for informational purposes but not as a limitation, with reference to the appended drawings in which:

[0027] [Fig-1] is a perspective view of a slicer comprising a device according to the invention;

[0028] [Fig.2] is a schematic view of a communication assembly comprising the slicer and the device according to the invention, one or more satellite networks, a base station, and a cellular communication network; and

[0029] [Fig.3] is a schematic view of the device according to the invention.

[0030] Figures 1 to 3 relating to the same embodiment, they will be commented simultaneously.

[0031] A trencher 10 with wheel 2 is a mobile machine, comprising a trenching wheel 2, intended to dig a trench in the ground as it progresses along a determined path.

[0032] At the rear of the wheel 2, relative to the direction of travel of the machine, a guide member 3 for the sheath 5 is installed, and makes it possible to unroll a sheath 5 at the bottom of the trench.

[0033] This guide member 3 comprises an upper structure 4 extending above the ground, the guide member 3 leading the sheath 5 to the bottom of the trench.

[0034] A location data acquisition device 1 according to the invention is fixedly installed on the structure 4.

[0035] The invention is not limited to the specific positioning of the device 1 on the structure 4, although it is advantageous to install the device 1 in one position, above the ground, and at a fixed distance from the sheath drop-off point 51 at the bottom of the trench. Also a position above the sheath guide member 3 is advantageous.

[0036] Thus, the device 1 and the drop-off point 51 must be able to be located on the same, non-deformable element of the kinematic chain which makes up the slicer 10.

[0037] The purpose of this device 1 is to locate with increased precision the sheath 5 deployed in the trench by means of the trencher 10.

[0038] This device 1 comprises a satellite geolocation unit 11.

[0039] This satellite geolocation organ 11 is a Geolocation and Navigation system by a Satellite System 30, called GNSS.

[0040] In this embodiment of the invention, the geolocation device 11 comprises a multi-band GNSS receiver (L1C / L2C / L10F / L20F / El / E5b / Bll / B21) connected to an ultra-sensitive active antenna.

[0041] In our embodiment, the data received from at least one GNSS system, for example the GPS constellation, BEIDU, Galileo, are received through an NMEA protocol, which is a standardized communication protocol comprising several variants (for example RMC, GNS). Also in the remainder of the description, reference may be made to an NMEA frame with reference to the geolocation data received from the satellite geolocation system.

[0042] The device 1 further comprises a cellular communication device 12, adapted to receive from a base station parameters for correcting the geolocation data.

[0043] In this embodiment, the cellular communication device 12 is adapted to communicate with base stations according to an RTCM (Radio Technical Commission for Maritime Services) standard, these base stations allowing the implementation of a satellite geolocation correction technique called real-time kinematics, RTK, from the English Real-Time Kinematic.

[0044] In this embodiment, the base stations 40 are a network of stations called NRTK (Network Real-Time Kinematic), but the invention is not limited to this single mode of implementation, a single RTK base station being able to be used.

[0045] The RTK thus implements base stations 40, whose geolocation is precisely known. The base station is adapted to calculate a correction measure of the information provided by the satellite network with which the device 1 communicates, in order to increase the location accuracy of the device 1. In the following discussion, we will speak of the frame received from the RTK base station 40 to refer to the geolocation positions corrected by the RTK base station 40, also called RTK station 40 or RTK relay 40.

[0046] Depending on the implementation modes, the RTK base station 40 may provide the corrected position or, in this embodiment, a correction value to be applied.

[0047] The typical nominal accuracy of RTK networks is of the order of 1 and 2 cm in planimetry and 2 to 3 cm in altimetry.

[0048] In this embodiment of the invention, the cellular communication device 12 comprises a device adapted to implement a cellular link of the LTE-LM category 1 type.

[0049] The device is configured to acquire positioning measurements at a predetermined frequency. This predetermined frequency is in our embodiment 1 measurement every 15 seconds. However, the frequency can be freely chosen depending on the desired precision, for example a measurement every 1 second to 24 seconds.

[0050] All of this data acquired by the satellite geolocation means 11 and by the cellular communication device 12 is stored in an internal data storage unit 15, for example here an internal hard disk, such as an SSD hard disk or a flash memory.

[0051] In practice, each time an NMEA frame is acquired, this frame is then transmitted to the RTK 40 station, via the cellular device, in order to obtain a corrected geolocation frame.

[0052] The RTK station is therefore requested each time data received from a GNSS system is acquired, in order to obtain a corrected value of the geolocation data obtained.

[0053] For this purpose, the device 1 comprises a control unit 13, such as a processor or a microcontroller, mounted in the device 1 and implementing a control method comprising the following steps:

[0054] - receive the NMEA frame from the satellite geolocation unit 11,

[0055] - transmit the NMEA frame to the RTK station to which the communication device is connected cellular communication;

[0056] - Calculate a corrected geolocation value based on the NMEA frame received and based on a correction parameter received from the RTK relay

[0057] - Save the corrected geolocation value in the internal memory 15.

[0058] However, it may happen that in operating conditions the RTK relay cannot be reached, for example because of a network outage with this relay.

[0059] When this situation occurs, the uncorrected geolocation data is then recorded, and the correction data will be recorded when it becomes available, for example when communication with the RTK 40 relay is restored or in a post-processing phase. In such a case, the calculation of the corrected geolocation value will be carried out during post-processing steps carried out on the post-processing device 50.

[0060] Indeed, the acquisition device 1 being installed on the upper structure 4 of the sheath guide, correction calculations of the measurements made are necessary to precisely obtain the position of installation of the sheaths or networks in the trench.

[0061] Therefore, post-processing calculations are performed to obtain more precise geolocation.

[0062] In order to limit energy consumption and simplify the on-board acquisition device 1, the post-processing calculation is therefore carried out on a post-processing device 50, such as a computer, a remote server or any suitable digital device.

[0063] This post-processing device 50 comprises in particular means for receiving the data recorded by the acquisition device. These may be remote communication means, such as means of communication on the internet, on an intranet, cellular or satellite communication means, or even means for reading a storage memory, such as a USB key, an external hard drive or any other data storage means, in particular adapted to be able to acquire the data recorded by the acquisition device 1.

[0064] The post-processing device 50 further comprises a calculation unit, such as a processor or any digital calculation means suitable for carrying out correction calculations in post-processing of the acquired data.

[0065] In order to calculate the exact position of the sheath, or of the cables, pipe or any element positioned in the trench, it is necessary to calculate a position of the sheath, taking into account the elevation of the device 1 relative to the ground, the depth of the trench, and the longitudinal and / or lateral offset of the point of deposit of the sheath at the bottom of the trench relative to the position of the device 1 on the upper structure 4 and the rotation of the upper structure 4.

[0066] Thus we can calculate the position of the sheath as being:

[0067] & sheath ^-device “ △x

[0068] Y sheath — ^device -

[0069] Z sheath — ^device - ^z + ^lit ^ext

[0070] Where:

[0071] (Xsheath the coordinates of the sheath in space; sheath 'sheath'

[0072] Xdevice\ the coordinates of the device in space; 1 device ^device

[0073] Ax is the longitudinal distance between the position of the device 1 and the point of deposit 51 of the sheath 5;

[0074] Ar is the lateral spacing between the position of the device 1 and the point of deposit 51 of the sheath 5;

[0075] A- is the vertical distance between the position of the device 1 and the point of deposit 51 of the sheath 5.

[0076] Dext is the external diameter of the installed sheath, cables or conduit.

[0077] Hlit is the height of the sand bed installed in the trench, if sand has been deposited.

[0078] In practice, the coordinates are converted from decimal degrees to Cartesian coordinates in order to apply the equations more simply.

[0079] The device 1 comprises in this embodiment an inertial unit 14.

[0080] This inertial unit 14 is particularly important for enabling correction of the rotational movement of the wheel at the rear of the slicer.

[0081] Under the effect of rotation, it happens that the wheel is no longer exactly, in its upper part, in line with the trench.

[0082] In other words, during its progression, the trencher sometimes gives an angle to the slicing wheel, which has the effect of laterally shifting the position of the device (in the upper part of the wheel support) in relation to the position of removal of the sheath. In this respect, the inertial unit makes it possible to reset the measurement vertically above the trench, taking into account the torque applied to the wheel.

[0083] The inertial unit also makes it possible to compensate for installation of the box on an inclined surface.

[0084] The data from the inertial unit are therefore acquired by the device 1, and recorded, then taken into account in the calculation of the refinement of the geolocation by the post-processing unit 50.

[0085] In a particular embodiment of the invention, this inertial unit 14 also makes it possible to avoid discontinuity in the measurements when the GPS signal is lost.

[0086] Indeed, when the trencher crosses a covered area, for example a heavily wooded area, the GPS signal may be lost.

[0087] In such a situation, and while the slicer continues its work, the inertial unit makes it possible to calculate an evolution of the position of the device 1 over a short period, in particular by measuring the accelerations of the device 1 in space. This way, it is possible to ensure continuity of measurement in all circumstances.

[0088] In this particular embodiment, it is also possible to envisage coupling the inertial unit to an odometer to improve the calculation of the progress of the trencher, for example when the connection to the GNSS network is lost.

[0089] The device 1 in this embodiment is energy autonomous, and for this purpose comprises a battery of electric accumulators 17.

[0090] However, the invention is not limited to this embodiment, and a device 1 according to the invention could be provided to be supplied by supply means of the slicer 10.

[0091] Furthermore, in order to perform a backup of data, an external memory reader 16 is installed in the device. This external memory reader 16 is for example an SD, micro-SD card reader, or a USB port, making it possible to connect an external memory and to copy the data stored on the internal memory 15 to the external mass media (SD reader or external hard disk, for example connected via the USB port).

[0092] This external memory is only a backup procedure, which is not intended to be accessible by the end user without opening the device. Although an alternative implementation could make it accessible to the user.

[0093] This external memory, such as an SD card, here acts as a useful backup device for recovering data, for example in the case where the server crashes or when a problem with the transmission of data by the device 1 does not allow transmission to the post-processing device 50 via here a cellular network or any type of radiofrequency data transmission network.

[0094] The device 1 further comprises communication means, such as a radiofrequency module, in the embodiment of the invention a Bluetooth® wireless communication module, or an input-output port, for example a USB port.

[0095] This radiofrequency module makes it possible in particular to connect a computer in order to configure the device 1 before its use.

[0096] In the current embodiment, a push button is installed on the device 1. A long press on this push button allows the device 1 to be started. A visual indicator, such as an LED, allows the device to be viewed whether it is functional or not. For example, the LED may flash when the device is in the process of acquiring data.

[0097] Once activated, the device 1 then acquires the geolocation and associated corrections at a predetermined frequency.

[0098] In this embodiment, but optionally, the data is then encoded via an encryption algorithm before being recorded in an internal memory 15.

[0099] The frames stored internally are the same as the frames transmitted by the cellular link. In addition, the voltage data of the battery 17 of the device 1, as well as the inertial data from the inertial device, are stored in the internal memory 15.

[0100] At each acquisition, the system systematically stores the data in the internal memory 15.

[0101] When a predetermined amount of data is reached, for example between 500kb and 2MB, and if the quality of the cellular connection allows it, the data is then transferred to the remote file post-processing device 50.

[0102] Alternatively, the data transmission may be performed at regular time intervals, for example every 2 to 5 minutes, regardless of the amount of data acquired.

[0103] Data remains stored until the memory is full. In this context, we speak of a First In First Out circular buffer, also abbreviated FIFO, so that when the memory is full, the oldest data is overwritten first.

[0104] In the event that the connection does not allow this transfer, it will be retried regularly until it is successful, for example every 5 minutes, or for any predetermined time value, for example between 30 seconds and 10 minutes.

[0105] The following data, which continue to be acquired, are then stored in memory and will be transferred to the post-processing device 50 once the previous data has been transmitted. - The post-processing device 50 further recovers data enabling the calculation of improved data such as: - The type of cable or pipe intended to be inserted into the sheath, in particular the diameter of the network installed; - The presence of a sand bed at the bottom of the trench and its thickness; - Height between the lowest point of the installer and the base of device 1; and - The address of the site and / or any useful administrative information.

[0106] The size of the internal memory is designed to allow the storage of several months of measurements. This helps avoid irretrievable data loss.

[0107] Note that the data consists of geolocation frames, corrected or not, possibly correction frames, battery voltage values ​​and inertial data, the whole being relatively small in volume compared to current storage capacities.

[0108] The data are made up in this embodiment of:

[0109] - the GNSS frame, incorporating positioning information and its quality (Weakening of horizontal precision known as HDOP, number of satellites in the network used, presence of RTK correction or not (for example in the case where the cellular network is unavailable);

[0110] - the date and time (extracted in particular from the NMEA frame of the satellite network employed, for example an RMC frame, as implemented in the main embodiment of the invention, or a GGA frame),

[0111] - the battery voltage at the time of capture;

[0112] And possibly other indications specific to the device allowing to know its state at each instant, in particular, in a particular embodiment, the inertial data acquired by an inertial unit.

[0113] The data thus transmitted to the post-processing device 50, or recovered via an external memory, allow the updating of topological databases allowing precise and reliable monitoring of the buried sheaths.

[0114] When the installation of the sheath is finished, the device 1 can be disconnected, for example by another long press on the activation push button.

[0115] Then all the data being acquired is stored in my internal memory and the device is turned off.

[0116] Optionally, another button, for example hidden under a shell of the device 1 allows, for example via a long press or any predetermined pressure sequence, to force a communication of the data to the post-processing device 50 or the generation of a copy of the data to an external storage memory connected to the input-output means. Nomenclature

[0117] • Data acquisition device 1 • Slicer 10 • Slicing wheel 2 • Sheath guide member 3 • Upper structure 4 • Sheath 5 • Satellite geolocation body 11 • Cellular communication organ 12 • Control unit 13 • Inertial unit 14 • Data storage unit 15 • 16 external memory reader • Battery 17 • Constellation of satellites 30 • Base station 40 • Post-processing device 50

Claims

1. Claims Post-processing device (50) characterized in that it comprises means for receiving data recorded on an acquisition device (1) of a slicer adapted to make trenches intended to receive a sheath (5), said slicer (10) comprising a slicing member (2), a sheath guide (3) and comprising an upper structure (4), and an acquisition device (1) fixed to said upper structure (4), said acquisition device (1) comprising: - a satellite geolocation unit (11) adapted to calculate geolocation data from signals emitted by at least one constellation of artificial satellites (30) - a cellular communication device (12) adapted to communicate with a base station (40) capable of providing a correction value for the geolocation data; - a control unit (13) adapted to receive from the geolocation device (11) a plurality of geolocation data and for each geolocation data, the control unit being adapted to send said geolocation data via the cellular communication device (12) to said base station; the control unit (13) being further adapted to receive from said base station (40) at least one correction value and to calculate a corrected geolocation data as a function of said correction value; and - recording means (15) for recording said corrected data; - an inertial unit, the recording means (15) being further adapted to record the data acquired from said inertial unit associated with the corrected data; said post-processing device further comprising a calculation unit adapted to calculate another correction of each corrected data item received from said acquisition device (1) as a function of parameters comprising a value of installation height of the device relative to the bottom of the trench, a value of longitudinal offset between said device (1), a point of deposit (51) of the sheath (5) at the bottom of the trench, a diameter value of said sheath, and data relating to a height of a sand bed in said trench, all of the data corrected by said post-processing device (50) forming a map of buried cables of sheaths and / or pipes laid by said trencher on which said acquisition device (1) is installed and said post-processing device being adapted to calculate another correction of said corrected data acquired as a function of the data acquired by the inertial unit of the acquisition device (1).

2. Post-processing device (50) according to claim 1, characterized in that it is adapted to associate with the recorded corrected data information relating to the nature of the cable intended to be inserted into the sheath and / or administrative location information of the installation location.

3. Post-processing device (50) according to any one of claims 1 or 2, characterized in that when the acquisition device (1) has not been able to calculate corrected data for acquired geolocation data, such as during a connection failure with said base station (40), said post-processing device (50) is adapted to calculate said corrected data as a function of the data recorded by said acquisition device (1) and as a function of a separately acquired correction value.

4. Assembly for establishing a map of buried cables of ducts and / or pipes comprising a trencher adapted to produce trenches intended to receive a duct (5), and a post-processing device (50) according to any one of claims 1 to 3, said trencher (10) comprising a slicing member (2), a duct guide (3) and comprising an upper structure (4), and a device (1) for acquiring geolocation data fixed to said upper structure (4), said acquisition device (1) comprising: - a satellite geolocation member (11) adapted to calculate geolocation data from signals emitted by at least one constellation of artificial satellites (30) a cellular communication device (12) adapted to communicate with a base station (40) capable of providing a correction value for the geolocation data; a control unit (13) adapted to receive from the geolocation member (11) a plurality of geolocation data and for each geolocation data, the control unit being adapted to send said geolocation data via the cellular communication member (12) to said base station; the control unit (13) being further adapted to receive from said base station (40) at least one correction value and to calculate a corrected geolocation data as a function of said correction value; and recording means (15) for recording said corrected data; - an inertial unit, the recording means (15) being further adapted to record the data acquired from said inertial unit associated with the corrected data, said acquisition device (1) of said slicer (10) being adapted to communicate with said post-processing device (50) via a communication member (12).

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