WO1995025942A1

WO1995025942A1 - Device for mapping flooded tunnels

Info

Publication number: WO1995025942A1
Application number: PCT/FR1995/000277
Authority: WO
Inventors: Marina Bardot; Olivier Bardot
Original assignee: Marina Bardot; Olivier Bardot
Priority date: 1994-03-18
Filing date: 1995-03-10
Publication date: 1995-09-28
Also published as: FR2717571B1; FR2717571A1; AU1953395A; EP0775289A1

Abstract

A device for mapping a three-dimensional space, particularly a flooded tunnel, comprising a first magnetic sensor (2) outputting a first electrical signal indicating the geographical orientation of the support holding said magnetic sensor (2), a tracking wire with a second sensor outputting a signal indicating the distance travelled from a reference point, and a third sensor outputting a pressure signal. Said device further comprises a computer for storing a data file corresponding to the signals from said three sensors.

Description

DEVICE FOR THE MAPPING OF UNDERGROUND UNDERGROUND GALLERIES.

The present invention relates to the field of topographic surveys for the purpose of mapping underground galleries. The mapping of submerged networks is carried out in the state of the art empirically by divers taking aimings and drawing, as they progress, a diagram of the gallery explored. Fiber optic tracking systems are also known as described in document JP-A-02302602 from NKK Corp which make it possible to determine a distance traveled by a mobile by measuring the light emitted as a function of the length of cable unwound. The major drawback of the known means lies in their imprecision or in the fact that the statements relate to only one dimension at each operation.

The objective of the present invention is to propose a simple handling device making it possible to carry out a rigorous mapping and with a high degree of precision, by means of an exploration by autonomous operators and not having an expensive equipment or bulky. To this end, the invention relates more particularly to a device for determining a mapping of a three-dimensional space, in particular for the mapping of flooded galleries, characterized in that it comprises a first magnetic sensor constituted, for example, by a magnetic compass or by a bi or tri-axial magnetometer, delivering a first electrical signal as a function of the geographical orientation of the support of said magnetic sensor, a second sensor delivering a signal as a function of the distance traveled, in particular a sensor delivering a signal as a function of the length of wire unwound from a reference point, and a third sensor delivering a pressure-dependent signal, the device further comprising a computer for storing a data file corresponding to the signals delivered by said three sensors.

The device uses exclusively portable means which can be supplied independently, and which do not require any prior infrastructure. It is therefore perfectly suited to implementation by individual divers operating without sophisticated logistical support. The memorized signals can be exploited after a mission by a computer tool for carrying out plots or determining the characteristics of the site explored.

According to a first embodiment, the magnetic sensor comprises means for fixing to the operator so as to maintain with the axis of progression of said operator a substantially constant angular position, the device further comprising its own clock circuit to periodically activate the storage of a new set of data corresponding to the instantaneous value of the signals coming from the sensors. The fixation is carried out for example on the diving suit, so that the magnetic sensor is oriented along the vertebral axis of the diver who can thus move with great freedom of movement without having to intervene on the operation of the device.

REPLACEMENT SHEET According to a second embodiment, the magnetic sensor is integral with a wire feeder, the device further comprising a button for manual activation of the data corresponding to the signals delivered by the sensors.

This technique makes it possible to carry out high-precision maps, by successive aims of the last reference point from a point of change of orientation and, moreover, to minimize the incidence of lateral displacements relative to the shortest trajectory, the the greater the distance between the reference point and the aiming point, the smaller the errors.

The two above-mentioned modes of implementation can moreover be combined with one another so as to allow computerized reprocessing of the data with a view to improving accuracy.

The invention is described in more detail in what follows, with reference to embodiments set out by way of nonlimiting examples, referring to the appended drawings where:

- Figure 1 shows a schematic view of a first embodiment; - Figure 2 shows a schematic view of a second embodiment;

The device for determining a mapping of a submerged network is described with reference to a nonlimiting example, of which FIG. 1 represents a schematic view of a first mode of implementation. Such a device is intended to reconstruct the trajectory of a diver (5) who explores a submerged gallery with an accuracy of the order of 5% (5 m of drift for 100m traveled). The diver (5) systematically marks the course he follows in the conduits which are often labyrinthine by unwinding a breadcrumb, nylon thread of about 2-3 millimeters in diameter wound on a reel. He fixes it in the gallery whenever possible friction threatens to cut this single guide which connects it to the surface. The trajectory of the diver (5) to be reconstructed is therefore a succession of broken lines circumscribed inside a gallery. The system consists of:

- a wire feeder (1) fitted with a counter for the number of turns made by the spool,

- a magnetic sensor (2) - a control unit (3) containing a pressure sensor.

The Ariane wire dispenser (1) contains a spool of cylindrical wire whose dimensions, at full load, are 65 mm in diameter and 165 mm in height. The diameter of the breadcrumb is between 1 and 3 millimeters, which corresponds to a total length of the

1000 meters or 250 meters. To count the number of turns, two means are possible: According to the first, the axis of the pulley is connected to a gear reducer 600 itself connected to a multi-turn potentiometer.

Each time the pulley turns, the potentiometer axis makes l / 600th which gives an analog image of the length of the unwound wire. *>

A preferred means consists of an element such as a magnet fixed in the movable flange of the reel (1). Each time the coil turns, this element activates a switch, for example of the flexible blade type (ILS) fixed on the frame of the reel (1), and generates a logic signal which increments a counter. Knowing at the start the radius of the winding, we count the number of turns made by the reel when the plunger (5) advances in the gallery. Each time the coil turns, a contact (open almost all the time) closes for a period which varies between 10 and 100ms depending on the rotation speed of the coil, respectively 75ms / revolution (fast speed, jerk ) and 800ms / revolution (slow speed). An average value is of the order of 50 milliseconds of contact for 1 revolution in 400 milliseconds. Thus the distance of unwound thread can be deduced from the number of turns counted in the direction of unwinding since the last initialization of the program. In the case where the reel always turns in the same direction, the number of turns counted varies between 1000 for 250 meters of wire of 3 millimeters in diameter and 3000 for 1000 meters of wire of 1 millimeters in diameter. The wire reel (1) further comprises a sensor for the direction of rotation of the spool in the event that the plunger (5) retraces its steps by rewinding its wire. The magnetic sensor (2) measures the projection of the earth's magnetic field on the horizontal plane for pitch and roll angles less than 60 °. It produces two direct voltages (Ux, Uy) proportional to the projection of the earth's magnetic field on the axes of the horizontal plane, along U _x = k H sin (θ) U _y = k H cos (θ), where: k is a constant θ designates the magnetic heading angle H designates the modulus of the earth's magnetic field. The Ux / Uy ratio therefore represents the tangent of the magnetic heading followed by the mobile. The accuracy of the magnetic sensor (2) must be +/- 1 °.

The housing (3) comprises a pressure sensor, for example hydrostatic, delivering an output voltage varying linearly between 0 and 200 mV for a pressure of 0 to 200 meters of water. The housing (3) has a series of control buttons:

- A button (11, FLX), signaling the fixing of the wire in the gallery, which makes it possible to locate the points of the wire fixed in the gallery and for which the taking of measurements is made according to a particular protocol exposed with reference to Figure 2 .

- A button (12, EX), signaling an exceptional event, which makes it possible to locate a particularly remarkable point in the gallery.

- A button (13, ON), which is energized by the plunger (5) and which, when pressed again, de-energizes the module.

- A signaling light consisting of a red LED (LED 1) which lights up to indicate that the module is under voltage and that a self-test has been carried out. - A button (14, CART), for activating (or deactivating) the measurement mode (CART mode), by the diver (5). As soon as it is activated, the microcontroller creates an initialization card which it will place behind the last card contained in the memory. This same button, pressed again, marks the end of the measurement. - A second indicator light consisting of a green LED (LED 2) which lights up to indicate that the module is starting to take measurements. There are mainly two operating modes for this navigation module.

- in the first, NAVIGATION mode, the diver (5) progresses through the gallery to be mapped while unwinding his breadcrumb. The magnetic sensor (2) is integral with the vertebral axis of the plunger (5) and permanently provides the direction of movement of the plunger (5). The measurements are triggered at very short time intervals and are interpreted in order to restore the continuous trajectory followed by the diver (5).

- in the second, TRAJECTOGRAPH mode, the magnetic sensor (2) is integral with the reel (1), mounted so that the plunger (5) can easily and precisely align the measurement axis of the magnetic sensor (2) and the wire tense. Preferably, the device for aligning the stretched wire with the measurement axis of the magnetic sensor (2) consists of a cradle supporting a laser diode movable in the vertical plane passing through the measurement axis of said magnetic sensor (2) . The diver (5) progresses through the gallery to be mapped by unrolling his breadcrumb, but only the points of attachment of the wire in the gallery are used for the topographic reconstruction of the gallery. In fact, before fixing the wire, he stretches it, aligns it with the measurement axis of the magnetic sensor (2) by cutting the wire stretched by the laser beam and presses the button (11, FLX). The measurement taken is then that of the orientation of the segment connecting the last two attachment points. All the measurements triggered by FLX are interpreted in order to restore the broken line formed by the breadcrumb trail fixed in the gallery. The box also contains a micro-controller card which aims to:

- regularly determine the points of the trajectory followed by the mobile,

- store these points in memory,

- establish a communication interface with a PC,

- restore these points in the form of a file. The navigation module entries are provided by:

- an altitude sensor (dimension z),

- a distance traveled sensor,

- a sensor signaling the fixing of the wire in the gallery,

- a magnetic heading sensor followed by the diver (5). After processing, the gallery mapping, carried out by the navigation module, is used in the form of:

- vertical section (x on the abscissa, z at altitude),

- horizontal section (x, y coordinates of the gallery points). The device attached to the reel allows the plunger (5), by actuating a simple button on the handle, to signal to the signal processing card that he is fixing the wire in the gallery. It will be useful to associate a number with each fixing action, for example by a counter incremented each time the button is pressed. According to a first method, the data acquisition is made at each logical interruption generated by the distance sensor. The following are stored in a file:

- the measurement number,

- the value of the 2 output voltages of the magnetic heading sensor, - the value of the analog voltage output of the distance sensor,

- the value of the counter for the number of times the wire has been attached to the gallery,

- the value of the analog voltage of the pressure sensor.

According to a second method, data acquisition is made every 4 logical interruptions generated by the distance sensor. The following are stored in a file: - the number of the file,

- the upper limit of the last 4 values of the wire fixing number counter,

- the arithmetic mean of the last 4 values of the 2 output voltages of the magnetic heading sensor,

- the arithmetic mean of the last 4 values of the analog output voltage of the distance sensor

- the arithmetic mean of the last 4 values of the analog voltage of the pressure sensor.

The diver (5) moves by palmning in the gallery and unrolls at the same time his breadcrumb; this is the case represented in FIG. 1. The magnetic sensor (2) is fixed on the neck of the plunger (5) and connected by a wire to a case (3) fixed to his wrist and comprising the card for recording the data. On the housing (3) are the FLX, EX, CART, ON buttons, the pressure sensor and the ultrasonic receiving transducer allowing wireless connection with the reel (1). On the reel (1), there are the distance and direction of rotation sensors of the coil as well as the ultrasonic transducer for connection with the box carrying the magnetic sensor.

A variant consists in replacing the link between the different modules of the device by means of synchronization of independent clocks integrated in each of the modules, the initialization of which takes place at the start of a mission and can be carried out by complementary means of communication. provided on each module. As an example, a magnetic switch of the I.L.S. type can be provided. activated by a magnet placed on the add-on.

Initialization is carried out by bringing two complementary modules together in a given configuration in which the magnet of each of the modules activates the the other module. The switch is connected to a clock reset input of the corresponding module.

The example of implementation described with reference to FIG. 2 corresponds to a motorized progression for explorations over very long distances, the diver (5) moving by means of a scooter and at the same time unwinding his breadcrumb. The magnetic sensor (2) is fixed on the propellant (20) and is connected by a wire to the recording box (3) also fixed on the propellant (20). On this box (3), there are always the FLX, EX, CART, ON buttons, the pressure sensor and the ultrasonic receiving transducer. On the reel (1), there are the distance and direction of rotation sensors of the coil as well as the ultrasonic emission transducer.

According to an alternative embodiment, the device further comprises a distance sensor to the walls (4), for example an ultrasonic sensor, positioned on the reel (1). The distance from the ultrasonic transducers to the walls of the gallery is very variable with the dimensions of said gallery, between 0.5 meters in the case of a narrow gallery and several meters, or even ten meters in the case of a wide gallery .

Another variant consists in providing on the box containing the magnetic sensor a set of telemetric sensors arranged on two axes perpendicular to the axis of progression of the operator. The sensors are driven in rotation around the axis of progression and thus deliver signals making it possible to produce an image of the cross section of the gallery. The diver (5) activates the power-on button - the LEDl (red) lights up - and attaches his breadcrumb in the gallery, to the point where he wants to start mapping. He then activates the button for switching to CART mode. The initialization card is placed behind the last card contained in the memory. LED2 (green) lights up. The diver (5) begins to unwind his breadcrumb. These data are recorded by the microcontroller of the on-board card in a saved memory. They are organized in the form of files which are compiled at each measurement. A measurement is triggered if:

- the contact of the reel number counter (1) turns from the open to closed position or button 1 (FLX) is pressed (contact mode), or - the time elapsed since the last measurement exceeds a predetermined value , for example 2 seconds (time delay mode), A digital file is then created and it contains the following elements.

- The measurement number (from 0 for the initialization sheet)

- The triggering mode (Pulse by contact -FLX included- or Time delay) - The direction of rotation of the coil

- The algebraic sum of the turns performed by the coil since the last initialization of the system.

- The value of Ux

- The value of Uy - The value of P, altitude rating

- The condition of the fixing point marker

- The condition of the remarkable points marker

In summary, a DATA RECORD sheet is presented in the following form

n ° DIMENSION TYPE FIELD

1 n ° of the measurement nb positive integer> at 0 <0.6000> V. initial 0

2 Pulse or Delay mode Initial pulse trigger value

3 directions of rotation of Positive (unwinding) Initial V. the coil or Negative (winding)

4 ∑ nb pulses (direction nb positive integer <0.3000> positive) -

∑ nb pulses (direction V. initial 0 negative) since the last initialization

5 Ux = analog voltage output voltage whose value <-10V, + 10V> on absolute channel X must be coded on 13 bits of the magnetic sensor (2) minimum V. initial 0

6 Uy = output voltage on analog voltage, the same value as absolute Y channel must be coded on 13 bits of the magnetic sensor (2) minimum V. initial 0

7 P = output voltage of the analog voltage whose value <0V, + 15V> absolute pressure sensor must be coded on 13 bits minimum V. initial 0

8 state of the point marker YES or NO Initial fixing value YES

9 state of the points marker YES or NO Initial value remarkable points YES

The data stored in the microcontroller must be transferred to the hard drive of a computer via an asynchronous RS 232 link. They are presented in the form:

- either an ASCII file to be processed by software written in Pascal or C,

- or a file that can be processed on a spreadsheet. The data processing software must have the following functionalities:

- view the initial file,

- create topographic files,

- archive topographic files.

The purpose of this archiving is to create files of a single type, TOPO type, intended to be viewed in the form of MAPS, from all of the topographic data or subsets and the physical parameters of the reel (1 ) necessary for the topography calculation, either:

- Ro (i), the starting radius of the winding during initialization,

- D (i), the length of the winding, - do (i), the diameter of the breadcrumb.

- Uxos (i), possible offset correction on channel X of the magnetic sensor (2),

- Uyos (i), possible offset correction on channel Y of the magnetic sensor (2), Two cases arise:

- case n ° 1: the diver (5) knows that the distance counter has not changed state between the end of a topographic SUB-ASSEMBLY (i) and the start of the next topographic SUB-ASSEMBLY (i + l), then:

Ro (i + l) = Ro (i) - do.ENT (X (i) (last record) / ENT (D / do)), equation in which X (i) (last record) is the algebraic sum of the pulses (field 5) of the file of the initial file corresponding to the last file of the SUB-ASSEMBLY (i). This situation corresponds to the case where the diver (5) has topography a section of the gallery, cut his wire, possibly extinguished then re-lit his module, then has started another topography further.

- case n ° 2: the diver (5) knows that the distance counter has changed state between the end of the SUB-ASSEMBLY (i) and the beginning of the SUB-ASSEMBLY (i + 1), then Ro (i + 1 ) is a value specified by the operator.

This situation corresponds to the case where the diver (5) has topography a section of the gallery, possibly extinguished then relit his module, then rewound part of his wire, noted on

Departure ro and started another topography further.

The filling of a file n of the TOPO file takes place in the different fields, considering that, for the calculations, the variables, in addition to those indicated above, are defined as follows:

Xi (n) = algebraic sum of the pulses (field 5) of the file (n) of the initial file θ (n) = magnetic heading angle associated with the length of the segment of wire between the point (n-1) and the point (not). Uxi (n) = voltage on channel X of the magnetic sensor, i.e. value of field 6 of the file (n) of the initial file

Uyi (n) = voltage on channel Y of the magnetic sensor, i.e. value of field 7 of the file (n) of the initial file Pi (n) = output voltage of the pressure sensor, this is ie value of field 8 of the file (n) of the initial file Kp constant scale factor whatever the value of Pi (n).

- Field n ° 1: point n ° (n) = point n ° (n-1) + 1

- Field n ° 2: n ° of the measurement taking of the corresponding file in the initial file - Field n ° 3: length of the wire segment between the point (n-1) and the point (n)

This length is calculated as follows: lg (n) = 2 π (Ro (i) - do.ENT (Xi (n) / ENT (D / do)))

- Field n ° 4: length of wire unwound between point (n) and point 0 This length is calculated as follows: d (n) = d (n-l) + lg (n),

(Uxi ((n) + Uxos (i)

- Field n ° 5: Cos θ (n) =

V (Uxi (n) + (Uxos (i)) + (Uyi (n) + (Uyos (i))

(Uyi ((n) + Uyos (i)) - Field n ° 6: Sin θ (n) =

V (Uxi (n) + (Uxos (i)) + (Uyi (n) + (Uyos (i))

Pi (n) - Field n ° 7: prof (n), depth of point n prof (n) ^:

Kp

- Field n ° 8: State of the fixing point marker

- Field n ° 9: State of the remarkable points marker The state of the fields in the form (n ° 0) for initializing a SUB-ASSEMBLY (i) is in the form:

- field n ° 1 = field n ° 2 = field n ° 3 = field n ° 4 = field n ° 5 = 0,

Pi (l)

- field n ° 6: prof = Kp

Pi (l) being the value of field 8 (Pressure) of the file of the initial file corresponding to point n ° 1 of SUB-ASSEMBLY i,

- field n ° 7 = field n ° 8 = YES.

Each SUB-ASSEMBLY, therefore gives rise to a file of the TOPO type. A TOPO file therefore looks like this:

TYPE FIELD

1 n ° of point nb positive integer (from 0) n ° of measurement nb positive integer (from 0) lg (n) = length of segment nb positive integer between point (n-1) and point nd (n) = length of unwound yarn nb positive integer between point n and point 0 cos (θ (n)) = cosine of the angle of real nb of <-l, +1> whose absolute value is cap magnetic of the segment coded on 13 bits between the point (n-1) and the point n sin (θ (n)) = sine of the angle of real nb of <-l, +1> whose absolute value is magnetic heading of the segment coded on 13 bits between the point (n-1) and the point n depth of the point n real nb of <0, +200> whose absolute value is coded on 13 bits state of the marker of the points of YES or NO fixing state of the marker of remarkable YES or NO points

From the recording of a series of TOPO files, we construct a TRAJECTORY, file of points associated with a MAP graphic, which allows you to view the information contained in this TRAJECTORY, file which contains relative coordinates of points, it is to say calculated in a reference having as origin the point n ° 0 of the TRAJECTOIRE.

There are three ways of building a TRAJECTORY:

- GROSS NAVIGATION mode,

- SMOOTH NAVIGATION mode,

- TRAJECTOGRAPHER mode. The coordinates of the points are calculated in a direct othonormed reference frame whose origin is point n ° 0 and the direction of the Y axis that of magnetic North. Once the TRAJECTORY has been constructed, the MAP can be viewed:

- in the original calculation reference,

- in a coordinate system where the absolute coordinates of the origin are specified. A TRAJECTORY sheet is in the form

The filling of file n ° 0, at initialization is: field 1 = field 2 = field 3 = 0 field 4 = prof (0) = prof (1) field 5 = field 6 = YES, field 6 doesn’t does not exist in the TRAJECTOGRAPHER mode described below.

In RAW NAVIGATION mode, the TRAJECTORY files are created from those of the corresponding TOPO file.

- Field 2 gives the value of the abscissa X of the corresponding point (k), according to

X (k) - X (k-1) ₊ lg (k) cos (θ (k)) J ^fik - ^

V lg (k) with prof (k), depth of point (k), value of field 7 of the file in the TOPO file corresponding to point (k).

- Field 3 gives the value of the ordinate Y of the corresponding point (k), according to

-prof (k) prof ^ ²

Y (k) = Y (k-1) + lg (k) sin (θ (k)) Λ ⁷ lg (k)

- Field 4 gives the value of the altitude Z of the corresponding point (k), according to Z (k) - = prof (k),

- Field 5 gives the state of the fixing point marker for point n ° (k).

- Field 6 gives the state of the marker of the remarkable points for point n ° (k).

In SMOOTH NAVIGATION mode, from the corresponding TOPO file, the

TRAJECTORY are made up of consecutive files, grouped, from 0, thanks to field 1, under the condition: lg (i) <1 meter i of the group

Field 3 gives the value of

Y (k) = Y (k-1) + (lg (i)

i du'gToupe Card na (group) ar na (group)

- Field 4 gives the value of the altitude Z of the corresponding point (k), according to ∑ prof (i)

7 / | <= ' ^du 9 ^rou P ^e

Cardinal (group)

- Field 5 gives the state of the attachment point marker for point (k), ie YES if field 8 of at least one of the points in the group is equal to YES. - Field 6 gives the state of the marker of the remarkable points for point (k), ie YES if field 9 of at least one of the points in the group is equal to YES.

In TRAJECTOGRAPHER mode, from the corresponding TOPO file, the

TRAJECTORY are selected on the condition that the state of the fixing point marker, field 5 of the file of the TOPO file is YES. - Field 2 gives the

X (k) = X (k-1) ⁺ (d (k)

- Field 3 gives the value of the ordinate Y of the corresponding point (k) according to Y (k) = Y (k-1) + (d (k) - d (k-1)) sin (θ (k) ) \ ^pr0 _d ^f ₍ ⁽ ^ _. ^" gg ^{" 1]}

- Field 4 gives the value of the altitude Z of the corresponding point (k), according to Z (k) = prof (k),

- Field 5 gives the state of the marker of the remarkable points for point n ° (k)

- Field 6 no longer exists.

The present invention is described in the foregoing by way of nonlimiting examples. It is understood that a person skilled in the art will be able to produce various variants without departing from the scope of the invention. In particular, the wire feed sensor can be replaced by any known displacement sensor, for example by a propeller sensor, an ultrasonic sensor or an electromagnetic sensor, for exploration applications in an aquatic environment.

Claims

1 - Device for determining a mapping of a three-dimensional space, in particular for mapping flooded galleries, characterized in that it comprises a first magnetic sensor (2) delivering a first electrical signal depending on the geographic orientation of the support of said sensor magnetic (2), a second sensor delivering a signal as a function of the distance traveled from a reference point and a third sensor delivering a signal as a function of pressure, the device further comprising a computer for storing a file of data corresponding to the signals delivered by said three sensors.

2 - Device for determining a mapping of a three-dimensional space according to the main claim characterized in that the magnetic sensor (2) comprises means for fixing to the plunger (5) so as to keep with the axis of progression of said plunger ( 5) a substantially constant angular position

3 - Device for determining a mapping of a three-dimensional space according to the main claim characterized in that the device further comprises a clock circuit capable of periodically activating the storage of a new set of data corresponding to the instantaneous value signals from the sensors.

4 - Device for determining a mapping of a three-dimensional space according to the main claim characterized in that the second sensor consists of a wire reel (1), integral with the magnetic sensor (2), the device further comprising, a manual data activation button corresponding to the signals delivered by the sensors.

5 - Device for determining a mapping of a three-dimensional space according to claim 4, characterized in that the wire reel (1) has a coil provided with an element capable of interacting with a switch to generate a logic signal incrementation of a digital counter.

6 - Device for determining a mapping of a three-dimensional space according to any one of the preceding claims, characterized in that the device comprises a computer for recording, at each logical interruption generated by the distance sensor, of data constituted at least through ;

- the number of the measurement recorded;

- the values of the two signals U _x and Uy delivered by the magnetic sensor (2);

- the value of the signal delivered by the pressure sensor. 7 - Device for determining a mapping of a three-dimensional space according to one of claims 4 or 5, characterized in that it further comprises a button (11, FLX) for generating a logic signal to signal the fixing of the wire d 'Ariane, the action on said button triggering the measurement, by the magnetic sensor (2) integral with the wire feeder (1), of the orientation of the stretched wire.

8 - Device for determining a mapping of a three-dimensional space according to any one of the preceding claims, characterized in that it further comprises a button (12, EX) for generating a logical interruption to signal a remarkable point, the action on said button also activating a logic signal.

9 - Device for determining a mapping of a three-dimensional space according to any one of the preceding claims, characterized in that it further comprises an ultrasonic distance sensor delivering a signal depending on the distance between the plunger (5) and the wall , measured in two perpendicular directions.

10 - Device for determining a mapping of a three-dimensional space according to one of claims 4, 5 or 7, characterized in that it further comprises a device for aligning the stretched wire with the measurement axis of the magnetic sensor (2), consisting of a cradle supporting a laser diode movable in the vertical plane, passing through said measurement axis of the magnetic sensor (2).

11 - Device for determining a mapping of a three-dimensional space according to any one of the preceding claims, characterized in that the second sensor is a propeller, ultrasonic or electromagnetic sensor, delivering a signal as a function of the relative speed of the plunger (5 ) with respect to the fluid, from which the distance traveled is deduced.

12 - Equipment for carrying out the mapping of a three-dimensional space characterized in that it is constituted by a computer equipped with means for calculating profiles from records made by the device according to any one of claims 1 to 1 1 and display of the reconstructed cartography.