Multi-element system for checking recesses of a fan disc using eddy currents

Abstract

One aspect of the invention relates to a device (20) for checking a cavity of a mechanical part made of an electrically conductive material by using eddy currents, the cavity opening on one side of the part and comprising an inner surface, the device being designed to be inserted at least partially into the cavity, the device comprising a plurality of probes (22) mounted on a support (21), each probe of the plurality of probes being geometrically consistent with at least a portion of the inner surface, and each probe comprising a plurality of coils (23) suitable for being in contact with the portion of the inner surface.

Description

DESCRIPTION TITLE: Multi-element system for eddy current control of cells in a blower disk TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of non-destructive testing of parts, particularly in aeronautics.

[0002] In particular, the invention relates to an eddy current control device for a cavity in a mechanical part made of electrically conductive material. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In aeronautics, the health of cavities, such as the fan disk recesses machined by broaching and used to hold the blades, is typically assessed using non-destructive testing (NDT) approaches. Eddy current (EC) probes are commonly used to detect defects in these cavities. However, these devices have a drawback: they cannot inspect the entire cavity within a reasonable acquisition time while maintaining high measurement resolution, typically for assessing defects on the order of centimeters. Furthermore, it is not always possible to precisely quantify the dimensions of defects in these cavities.

[0004] Indeed, due to the complexity of the cavity wall geometry, CF sensors cannot monitor every part of the cavity, particularly the curved sections of the alveoli, along their entire length in a single acquisition. The probe used is a single-element probe that must be moved several times within the cavity, each time to inspect a different portion along its entire length. Furthermore, these commonly used probes require calibration, using a reference piece, each time they are moved to inspect a different part of the cavity, typically another curved section.

[0005] Consequently, the time required to acquire signals via the probe across all cavities of a part can reach several hours. These acquisition times are therefore incompatible with a production or maintenance environment, or with workshop operations.

[0006] Furthermore, since these types of probes require operator intervention to position them from one portion to another, their use generates significant measurement uncertainties due to the operator's intervention. In addition, because the operator must move the probe several times per cavity, typically for each curved section of a socket, the risk of overlooking a portion of the cavity is high.

[0007] Therefore, there is a need to improve CF control of cavities, such as alveoli. SUMMARY OF THE INVENTION

[0008] The invention offers a solution to the problems mentioned above, by allowing, via a suitable device, the simultaneous inspection of several parts of the internal wall of a cavity.

[0009] One aspect of the invention relates to an eddy current control device for a cavity in a mechanical part made of electrically conductive material, the cavity opening on one side of said part and comprising an internal surface, the device being adapted to fit at least partially into the cavity, the device comprising a plurality of probes mounted on a support, each probe of the plurality of probes being geometrically shaped to a part of the internal surface, and each probe comprising a plurality of coils adapted to be in contact with the part of the internal surface.

[0010] The term "cavity" refers to a hollow with a regular geometry, machined into the workpiece. This cavity can be narrow and elongated in cross-section, for example, a hole machined by broaching.

[0011] The term "opening" means that the cavity is open at one end of the part being inspected.

[0012] The term "geometrically conformed" means that the external geometry of a probe is adapted to cooperate with that of the corresponding portion of the internal surface. Therefore, there is a coincidence between the shape of the probe and the shape of the portion in question.

[0013] The term "in contact" means that the air gap is zero between the internal surface of the cell and each coil.

[0014] This device allows for the inspection of multiple parts of a cavity within a mechanical component made of electrically conductive material, such as a metal part, in a single scan to detect and characterize defects. This reduces the acquisition time required to inspect the entire cavity, and therefore all cavities within the part, if applicable. Sensor calibration time is also reduced since the probes can be calibrated simultaneously, rather than sequentially as with conventionally used devices.

[0015] Such a device also reduces the sensitivity of the measurement to human factors, that is, it reduces the measurement uncertainty related to operator intervention. "Measurement uncertainty" refers to an approximation error in the acquired data due to a set of experimental parameters affecting the accuracy of the measurement.

[0016] Furthermore, this device minimizes probe misplacement since the probes are specifically designed to inspect their respective parts of the component. Therefore, in the case of a cavity with a complex geometry, the risk of mispositioning the probes is significantly reduced. In other words, the positioning of this device offers high repeatability.

[0017] Finally, the use of multi-element eddy current probes, i.e., those with several coils, makes it possible to reduce the number of passes and improve the measurement resolution.

[0018] In addition to the characteristics just mentioned, the device according to the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0019] In one embodiment, the portion of the internal surface extends in a longitudinal direction of the cavity.

[0020] The term "longitudinal direction" refers to the direction of the largest dimension of the cavity. In the case of a cavity, this is the direction parallel to the curved parts, in this case parallel to the generatrices, that is to say parallel to the direction of machining of the cavity.

[0021] In one embodiment, each probe of the plurality of probes is mounted on the support via a retaining element, the retaining element being capable of holding each probe in contact with the portion of the surface to which said probe is conformed.

[0022] The probes' contact with the cavity wall is achieved and maintained by a mechanism adapted for this purpose, throughout the control and movement of the device in the cavity.

[0023] In one embodiment, the retaining element is a spring or a cylinder.

[0024] In one embodiment, the plurality of coils of each probe is arranged in several parallel rows, each coil of each row of the plurality of rows being spaced a predefined distance from the adjacent coils within said row, and the coils of two adjacent rows are arranged in a staggered pattern.

[0025] The staggered arrangement increases the measurement resolution and improves the detection and characterization of defects along the cavity wall.

[0026] In one embodiment, the predefined distance is between 0.5 mm and 2 mm.

[0027] Such a distance between the different coils of the same probe makes it possible to achieve an accuracy on the order of a millimeter, for example between 0.5 and 2 mm, for the detection, localization and characterization of defects.

[0028] In one embodiment, the plurality of coils of each probe of the plurality of probes is arranged in three parallel rows, each row comprising five coils.

[0029] The use of three rows of coils makes it possible to maintain a resolution on the order of a millimeter, thanks to measurement redundancy induced by the proximity of the coils, even if one or two of these coils malfunction or stop working.

[0030] In one embodiment, each probe of the plurality of probes is made of a flexible material.

[0031] The use of a flexible material ensures that the probe's geometry conforms to the corresponding part of the internal wall, even in cases of wall irregularities or deviations where probe conformity could not otherwise be guaranteed. Furthermore, flexible probes can be inserted without any retaining device, as they can then be pressed directly into the cavity. The natural elasticity of the probe material would then ensure that the probe coils remain in contact with the internal cavity wall.

[0032] In one embodiment, the part is a rotating element of an engine, and the cavity is a socket.

[0033] In one embodiment, the cavity is of the dovetail type, and each part of the internal surface is a curved part of the internal wall extending along the longitudinal axis.

[0034] It is therefore possible to use such a device to control fan disk cells of aircraft engines such as the CFM56 and LEAP engines.

[0035] Another aspect of the invention relates to an eddy current control system for a cavity in a part, the system comprising the device and a manipulator adapted to insert and move the device in the cavity.

[0036] This system allows for the automatic movement of the device for insertion and guidance throughout the cavity. The manipulator thus provides better probe guidance than the current solution for passage within the cavity. The manipulator can be adapted to be inserted at least partially into the cavity.

[0037] In one embodiment, the system further includes an analysis module configured to detect an acquisition error by one of the reels of the plurality of coils of one of the probes of the plurality of probes, and to emit an indication relating to the detected acquisition error.

[0038] This allows the operator to be notified that a measurement error has occurred. The operator can then repeat the measurement, possibly correcting the source of the error to complete the cavity inspection.

[0039] In one embodiment, the cavity is open throughout the part, and the part is raised on one or more wedges, the wedges being adapted to guide the device out of the cavity.

[0040] This allows the cavity to be inspected along its entire length without having to turn the part over during the inspection. The shims are therefore manufactured to guide the device until it exits the cavity.

[0041] In one embodiment, the wedge(s) are adapted to form a continuity of a cavity geometry outside the part.

[0042] In particular, the geometry of the shims is such that it forms a geometric continuity with the geometry of the cavity. That is to say, each shim used has a cavity whose shape is geometrically adapted to form a continuity with the geometry of the part's cavity. Thus, the device can be guided out of the cavity without altering the fluidity of its movement and therefore without degrading the quality of the measurement by the probes. It should be noted that the geometry of the part's cavity here refers to the internal geometry of the cavity, which can be quite complex, as is the case with a hollow. In other words, the geometry of the part's cavity is reproduced in the cavity of each shim. The shim is then positioned relative to the part so that the cavity of the shim extends the geometry of the cavity.

[0043] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0044] Other features and advantages of the invention will become apparent from the description, which can be read in conjunction with the figures. These figures are provided for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] Figure 1 represents a dovetail alveolus-type cavity.

[0046] Figure 2 represents an eddy current control device according to one embodiment.

[0047] Figure 3 shows a bottom view of the device as shown in Figure 2.

[0048] Figure 4 represents an eddy current control device according to another embodiment.

[0049] Figure 5 shows the control device of Figure 4 from a different viewpoint.

[0050] Figure 6 shows the control device of Figure 4 from a different viewpoint.

[0051] Figure 7 schematically represents a system comprising the device according to one embodiment.

[0052] Figure 8 is a schematic illustration of a display of data acquired via a device according to one embodiment of the invention.

[0053] Figure 9 represents another embodiment of the device according to the invention.

[0054] Figure 10 represents an embodiment of a manipulator to control the movement of the device according to Figure 9.

[0055] Figure 11 represents a standard part for calibrating the control device according to the invention. DETAILED DESCRIPTION

[0056] The invention relates to an eddy current (EC) testing device adapted for inspecting the internal surface of a cavity machined in a mechanical part made of an electrically conductive material, such as a metal part. The cavity opens on one side of the part. The invention is advantageously suited for inspecting narrow and elongated cavities, that is, cavities that have a significantly larger dimension along a longitudinal direction than a cross-section of the cavity along a transverse direction, and whose internal geometry is regular, as is the case for honeycomb structures.

[0057] By "regular geometry" we mean that the geometry of the cavity does not include abrupt variations in relation to the dimensions of the cavity, particularly along the longitudinal direction, typically the depth, of the cavity.

[0058] The use of the device according to the invention is illustrated below for inspecting the cells of a rotating element of an engine, more particularly a fan disc of an aircraft turbomachine. It should be noted that this device can advantageously be used for other types of cavities besides cells.

[0059] In order to reduce the acquisition times of CF inspection methods classically used in industry, the proposed device allows several parts of the cavity to be inspected simultaneously, thus avoiding having to reposition the probe used in several places.

[0060] By way of illustration of the problem solved by the invention, the cavity 10 in Figure 1 is a dovetail-type alveolus 10, schematically simplified. This type of cavity is typically machined on the fan discs of aircraft engines, for example, in the CFM56 series engines, such as the CFM56-5B and CFM56-2 models, and in LEAP engines, such as the LEAP1A / 1C and LEAP-1B models. Inspecting the various curved sections 11 of the cavity, four in number in this example, requires, using conventional methods, placing a CF probe in contact with the inner wall 12 of the cavity in one of the zones A, B, C, or D, each zone corresponding to one of the curved sections 11, moving the probe along the longitudinal direction of the cavity, and then repeating the inspection for one of the other zones. In contrast, the device according to the invention eliminates these constraints.

[0061] As illustrated in Figure 2, the device 20 includes a support 21. This support is used to assemble several probes 22 together. The probes of the plurality of probes are therefore mounted on the support, either directly or via a retaining element, which is described later.

[0062] The device 20 is adapted to be inserted into the cavity 10, at least partially. In other words, the support 21 and the probes 22 are adapted to be inserted, at least partially, into the cavity 10. The device 20, and therefore its components, are also adapted to be moved within the cavity 10, after insertion. The displacement is for example a sliding or translation of the device 20 in the cavity 10, along its longitudinal direction.

[0063] Each probe 22 is adapted to conform geometrically to a portion of the inner wall 12 of the cavity 10. That is, the geometry of the probe coincides with the geometry of the portion of the inner surface 12 to be inspected. In the case of a socket, the inspection may involve checking its curved portions 11. Each probe is therefore geometrically shaped to one of the curved portions 11 corresponding to one of the zones A, B, C, or D. The different portions of the inner surface to be inspected each extend along the longitudinal direction of the cavity.

[0064] In other words, to inspect the four curved parts 11 of the alveolus 10 shown schematically in Figure 1, the device 20 includes four probes 22, each having a geometry adapted to coincide with or fit the geometry of the curved part 11 in one of the relevant zones A, B, C or D.

[0065] The probes 22 are also of a sufficiently compact shape to allow the assembly of several probes 22 on the support 21 while ensuring that these probes can be inserted into the cavity 10 and moved along their afferent part of the internal surface 12.

[0066] Each probe 22 in the plurality of probes 22 comprises coils 23, forming a plurality of coils 23. Each probe 22 is therefore a multi-element probe 22. The coils are assembled to be in contact with the internal surface 12 to be inspected. The coils are thus arranged according to the geometry of the probe to fit the portion of the internal surface 12 that they serve to inspect. The coils are, for example, assembled on the external surface of the probes 22.

[0067] To achieve a resolution of between 0.5 mm and 2 mm for control, for example 1 mm, the coils 23 on each probe 22 can be arranged to form rows, for example parallel rows. Each row can contain the same number of coils 23 or a different number of coils 23.

[0068] Within the same row, adjacent coils can be separated by the same predefined distance, for example between 0.5 mm and 2 mm, such that 1 mm is equal to 2 mm. In other words, each coil in a row is separated from the The predefined distance is relative to its adjacent coil(s) in the same row. Therefore, there is a gap equal to the predefined distance between two adjacent coils in the same row of a probe. The predefined distance can be the same for each row.

[0069] A coil is considered adjacent to another within the same row when there is no other coil between them within that row. An adjacent coil is therefore a coil directly next to the coil in question. An adjacent coil is thus the coil that precedes or follows the coil in question in the row of coils.

[0070] It is also possible for the reels in two adjacent rows to be staggered. This results in an offset of each row relative to the other rows, along the axis of alignment of the reels within a row. This offset can be, for example, equal to half the predefined distance. In this case, assuming that the rows of reels are all spaced equally apart along an axis perpendicular to the axis of alignment of the reels within a row, each reel is equidistant from the two nearest reels in each adjacent row (i.e., from the four nearest reels in the two adjacent rows).

[0071] A row is adjacent to another when there is no other row between them. An adjacent row is therefore a row directly next to the row in question. An adjacent row is thus the row that precedes or follows the row in question by a plurality of rows.

[0072] The term "coil alignment axis" refers to the axis along which the coils are aligned in the same row.

[0073] In one embodiment, the distance between the two nearest coils in two adjacent rows is between 0.5 mm and 2 mm. For example, this distance can be equal to the predefined distance. Thus, there is the same spacing between adjacent coils in the same row and the nearest coils in different rows. Therefore, in this particular embodiment, each coil of a probe is spaced the predefined distance from all its neighboring coils, whether they are in the same row or a different row.

[0074] As an example, each probe comprises three rows of five coils.

[0075] On each probe, the coils can be placed at any location on its external surface that is in contact with the portion of the internal cavity surface. For example, the coils are located in a central part of the probe, situated between the first third and the second third of the probe's height.

[0076] The coils have, for example, a diameter greater than or equal to 0.5 mm, for example greater than or equal to 1 mm.

[0077] To power the coils, each probe may include a power supply circuit (not shown) within the probe itself. The power supply circuit may include a set of cables and / or an electronic board configured to control the transmitting and receiving coils and to transfer the measured magnetic field to an analysis module.

[0078] In one embodiment, the power supply circuit transmits the magnetic field measured by each coil to an output cable 26, which connects the probe circuit to an analysis module. The output cables 26 are bundled together in a housing 25 to form a harness 27 comprising the plurality of output cables 26. The housing 25 can be assembled to the support 21 and thus be integral with the device 20, or be part of a system including said device 20. The output cables 26 are also adapted to supply the power supply circuit in each probe to power the corresponding coils.

[0079] In one embodiment, the support 21 is partially inserted into the cavity. In other words, only the portion of the support onto which the probes 22 are mounted is inserted into the cavity. For example, in the case of a socket, the support 21 is not fully inserted into the cavity; a portion protrudes from the socket through the opening 13 of the socket 10. This allows the support to be held manually or with a dedicated module in order to move the device 20 along the cavity. For example, the support 21 comprises a front portion 24a that is inserted into the cavity with the probes 22, and a rear portion 24b that is not inserted into the cavity, typically because it protrudes from the socket through its opening.

[0080] In one embodiment, each of the probes 22 is mounted on the support via the retaining element 24, as illustrated in Figure 3. The retaining element 24 is, for example, a spring or a jack and serves to hold each of the probes 22, and therefore the coils 23 it comprises, in contact with the portion of the internal surface to which said probe 22 is conformed. The retaining element thus exerts a compressive force on the probes 22 by bearing against the support 21 to obtain an air gap of zero thickness. The spring can be any type of spring mechanism, for example, a helical spring, a metal spring, a leaf spring, etc.

[0081] Furthermore, the retaining element, such as the spring or the jack, can be used to retract the probes 23 onto the support 22, i.e., to reduce the distance between the support and the probes in order to facilitate insertion of the device into the cavity. Once the device is inserted into the cavity, the retaining element can perform its function of holding the probes firmly against the inner wall.

[0082] Each retaining element 24 is therefore located between the related probe 22 and the support 21. Furthermore, each retaining element can be located at the height of the coils of said probe, that is to say, be located between the first third and the second third of the height of said probe.

[0083] In one embodiment, one or more of the probes in the plurality of probes are made of an elastically deformable material, for example, a plastic sheet. "Flexible" is understood to mean a material that deforms elastically under the effect of an external stress or force, as is commonly known in the prior art. The use of such a material eliminates the need for a retaining element to hold the probes in contact with the inner wall. This effect is achieved by the elastic nature of the material, which is then pressed into the cavity to take advantage of its elasticity. However, the retaining element can also be used in this embodiment to, for example, facilitate insertion of the device into the cavity and / or improve control.

[0084] In one embodiment, as illustrated in Figures 4 to 6, which represent different viewpoints of the device 10, each probe 22 of the device 20 comprises an end 22a, which is curved from the surface external probe towards support 21. Such a shape allows the device 20 to be inserted and slid more easily into the cavity.

[0085] In the example provided, a probe is also assembled on the support, specifically on the front part 24a, in order to inspect the bottom of the cell.

[0086] In one embodiment, the cavity opens on both sides of the part. The part can then be raised on one or more supports. The geometry of these supports is such that they are adapted to guide the device out of the cavity. In other words, the supports are manufactured to maintain the continuity of the cavity geometry outside the part, guiding the device as it exits the cavity while ensuring that the contact provided by the retaining element and / or the flexible material of the probes is maintained until it exits the cavity.

[0087] Another aspect of the invention relates to an eddy current control system 30 for the cavity of the part, as illustrated in Figure 7. The system 30 comprises the device 20, as described above, and a manipulator 31. The manipulator 31 is used to automatically insert and move the device 20 within the cavity 10 throughout the acquisition. The manipulator is also adapted to move the device 20 to another cavity 10 for acquisition. The manipulator 31 and the device 20 are assembled via an assembly element 32, for example, which is adapted to be fixed to a fixing element 21c of the support 21.

[0088] The system may also include an analysis module 33, such as the one mentioned above. The analysis module 33 is configured to collect the data measured by the probes. It therefore includes instructions, for example in memory, that allow the acquisition and analysis of the data generated by the probe coils when these instructions are implemented, for example, by a processor. This analysis module may include a multiplexer, known in itself, for collecting the data generated by the coils.

[0089] The analysis module can also be configured to control the device's movement by driving the manipulator or sending movement commands to it. The analysis module therefore also includes instructions for performing this movement and / or generating these movement commands. To this end, the analysis module or the manipulator may include An encoder, known in itself, is configured to determine the position of the manipulator and / or device relative to the part. The encoder also allows each measured data point to be associated with a position on the part, thus automatically and precisely locating the position of a defect within the inspected cavity. Alternatively, the encoder is located within system 30 but is external to the analysis module 33 and the manipulator 32.

[0090] The analysis module can also be configured to detect an acquisition error by one of the coils. That is, it can detect that a coil is not functioning or is malfunctioning, for example, because no data from that coil is being received by the analysis module. The analysis module can then be configured to issue an indication, such as an alert, to indicate that an acquisition error has occurred. The analysis module can therefore include instructions to implement the detection of the acquisition error and the re-issuance of the associated indication.

[0091] The analysis module 33 can also include a storage memory configured to retain the acquired data and, optionally, the device positions associated with each data point relative to the part. This improves the traceability of the inspections.

[0092] The system 30 may also include a display module, for example a screen, comprising a plurality of pixels. This display module is, for example, included in the analysis module 33. The analysis module can then also be configured to transmit data to be displayed on the display module. The display on the display module can be implemented to present the acquired data, as illustrated in Figure 8. In this case, the display can be subdivided into a plurality of portions, each associated with one of the probes 22 of the device 20. In this embodiment, the device comprises four probes whose corresponding display portions are numbered from 1 to 4. Each portion is itself subdivided into a plurality of lines, each line corresponding to several pixels of the display module. Furthermore, each line corresponds to one of the coils of the probe associated with the portion containing said line.The time axis indicates the different times at which data was acquired via the probe coils. Thus, each pixel on each line corresponds to one of the data points measured by the corresponding coil at a given time. The display on the display module can be updated in real time, enabling detection. that an acquisition error occurs due to missing data in one of the lines. Furthermore, the display allows for easy identification and characterization of the presence of a defect. For example, the detection and characterization of an infinite slot defect 42 or notch defects 41 can be performed by reading the display. The display may also include an indication to show the location within the cavity of the part corresponding to each pixel. It is then possible to determine the defect's position within the cavity. In addition, a portion 43 of the display, comprising several pixels, may correspond to a point during the acquisition when the device has moved out of the cavity and indicates that no more data is being acquired. This portion therefore indicates the end of the cavity inspection and that another cavity can be inspected.

[0093] Figure 9 shows another embodiment of the device 20. Figures 9(a), 9(b), and 9(c) present the device 20 from three different viewpoints. This allows for an appreciation of the compactness of the device 20 and the conformity of the probes 23 to the geometry of the curved sections of a blower disc cavity. In this embodiment, the retaining element 24 is a thin arm, i.e., with a thickness between 1 mm and 2 mm, forming a bend from the support 21 to the probe 22, which it connects to said support 21. The retaining element 24 is, for example, a metal spring or a leaf spring, known in themselves. The housing 25 for collecting the output cables 26 is mounted on the support 21 to be at a distance from the probes 22.

[0094] Figure 10 shows another embodiment of the manipulator 31. The support 21, on which the probes 22 are assembled, is mounted on the manipulator 31. In particular, the support 21 and the housing 25 are mounted on a sliding element 31a of the manipulator. This sliding element 31a is the part of the manipulator adapted to insert the device 20 into the cavity 10. In this case, the manipulator 31 shown in Figure 10 is adapted to be placed in contact with an upper part of the workpiece, so that the sliding element can slide in or along the cavity, for example, by means of a rail or guide of the manipulator into which the sliding element is inserted. The sliding element and the rail or guide may have a straight or non-straight shape, for example, curved, in order to to adopt a movement trajectory corresponding to the geometry of the cavity. The manipulator shown in Figure 10 is, for example, adapted to inspect the cells of a blower disk which have a predefined radius of curvature in the thickness of the part.

[0095] In one embodiment, a standard part 100, as illustrated in Figure 11, can be used to calibrate the probe coils on reference cavities 10, for example, recesses, comprising known and calibrated defects at various locations on the internal walls of these cavities, for example, infinite crack 14 or notch 15 type defects. The device according to the invention is then inserted and moved into one or more of these cavities 10 in order to calibrate the probes before and / or after acquisition on the inspected part. The advantage of such a device is that the calibration is performed in a single pass of the device in the reference cavity, and not once per curved section as is conventionally done.

[0096] By way of illustration, the device 10 according to the invention was used to inspect 24 cells of a blower disc of a CFM56 engine. The total acquisition time to inspect all the curved parts of the cells was approximately 30 minutes. With a conventionally used sensor, the acquisition time is, comparatively, approximately 6 hours.

Claims

DEMANDS

1. Eddy current testing system (30) for a cavity (10) of a mechanical part made of electrically conductive material, the cavity (10) being open throughout the part and having an internal surface (12), the system (30) comprising: - an eddy current control device (20) of the cavity (10), the device (20) being adapted to be inserted at least partially into the cavity (10), the device (20) comprising a plurality of probes (22) mounted on a support (21), each probe (22) of the plurality of probes (22) being geometrically shaped to a part of the internal surface (12), and each probe (22) comprising a plurality of coils (23) adapted to be in contact with the part of the internal surface (12); - a manipulator (31) adapted for inserting and moving the device (20) into the cavity (10); characterized in that the system (30) further comprises one or more wedges for raising the part, the wedge(s) being adapted to guide the device (20) out of the cavity.

2. System (30) according to claim 1, wherein the wedge(s) are adapted to form a continuity of a geometry of the cavity (10).

3. System (30) according to any one of the preceding claims, wherein the portion of the internal surface (12) extends in a longitudinal direction from the cavity (10).

4. System (30) according to any one of the preceding claims, wherein each probe (22) of the plurality of probes (22) is mounted on the support (21) via a retaining element (24), the retaining element (24) being capable of holding each probe (22) in contact with the portion of the surface to which said probe (22) is conformed.

5. System (30) according to claim 4, wherein the retaining element (24) is a spring or a cylinder.

6. System (30) according to any one of the preceding claims, wherein the plurality of coils (23) of each probe (22) is arranged in several parallel rows, each coil (23) in each row of the plurality of rows being spaced a predetermined distance apart from the adjacent coils (23) within said row, and wherein the coils (23) of two adjacent rows are arranged in a staggered pattern.

7. System (30) according to any one of the preceding claims, wherein each probe (22) in the plurality of probes (22) is made of a flexible material.

8. System (30) according to any one of the preceding claims, further comprising an analysis module (33) configured to detect an acquisition error by one of the coils (23) of the plurality of coils (23) of one of the probes (22) of the plurality of probes (22), and to issue an indication relating to the detected acquisition error.

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