Manufactured part having a marker

Abstract

Manufactured part (100) comprising at least one electrically conductive component providing the manufactured part (100) with a given magnetic response upon exposure to a predetermined magnetic field variable over time, characterized in that the manufactured part (100) comprises at least one marker (110) arranged to modify the given magnetic response of the manufactured part (100), in order to provide the marked manufactured part (100) with a specific and predetermined magnetic response.

Description

DESCRIPTION TITLE: Manufactured part with marker Technical field of the invention

[0001] The present invention relates generally to manufactured parts, and in particular, the present invention relates to manufactured parts comprising a marker for the purposes of production control, maintenance, traceability, authentication. State of the art

[0002] It is known in the prior art to include markers on manufactured parts for production control, maintenance, traceability, and authentication purposes. However, these markers can affect the aesthetic appearance if they are visible, require disassembly if they are embedded within the manufactured part, and necessitate specific and complex equipment if, for example, these markers are engravings that can only be read with specialized optical equipment. Description of the invention

[0003] One object of the present invention is to address the disadvantages of the prior art mentioned above and in particular, first of all, to provide a manufactured part comprising a marker for the purposes of production control, maintenance, traceability, authentication, and which is simple and / or reliable to manufacture and / or control, and / or trace, and / or authenticate.

[0004] To this end, a first aspect of the invention relates to a manufactured part, comprising at least one electrically conductive component providing the manufactured part with a given magnetic response to exposure to a predetermined and time-varying magnetic field, characterized in that the manufactured part comprises at least one marker arranged to modify the given magnetic response of the manufactured part, in order to provide the marked manufactured part with a specific and predetermined magnetic response.

[0005] According to the implementation described above, the marker provides a specific and predetermined magnetic response to exposure to a time-varying magnetic field. Consequently, it is possible to distinguish a manufactured part equipped with such a marker from one without. In other words, the presence of the marker in the manufactured part ensures a difference (typically compared to the same manufactured part but without the marker) in the magnetic response during, or following, exposure to a time-varying magnetic field.

[0006] It is worth noting that the specific and predetermined magnetic response can be an absence of signal in response to exposure to a predetermined and time-varying magnetic field. Indeed, materials can be deliberately chosen that do not react to exposure to a predetermined and time-varying magnetic field. According to this implementation, the marker can be chosen so as not to disturb the predetermined and time-varying magnetic field, and this absence of disturbance constitutes the specific and predetermined magnetic response, that is, a particular signature.

[0007] The marker can be integrated into a specific manufacturing stage to verify that the manufactured part has indeed undergone that particular stage. The marker's presence can be checked during a final manufacturing operation, or during maintenance or overhaul, to ensure the manufactured part's conformity. A coding system using one or more markers can also be implemented, for example, to indicate the origin of the manufactured part (supplier, manufacturing line, etc.).

[0008] In other words, the marker is a marker that modifies the magnetic response of the manufactured part, that is to say, it provides a signature particular magnetic field, and - which can be chosen or located so as not to affect the visual appearance of the manufactured part, thus improving the perceived quality, - whose detection can be carried out simply by exposure to a time-varying magnetic field.

[0009] There are many possibilities for placing the marker in the manufactured part, so the design is easier, because as mentioned above, there is no need to necessarily provide direct access for optical reading, nor to necessarily provide access or disassembly to access the marker.

[0010] Generally, the manufactured part includes at least one electrically conductive component (this component may also be the marker), and exposure of this electrically conductive component to a time-varying magnetic field causes electric currents to flow through it, generating a magnetic field opposite to the applied magnetic field. The electrically conductive component, by modifying the applied magnetic field, thus determines a measurable magnetic response. The presence of the marker (a separate element or a local modification of a component) in the manufactured part is intended to modify the magnetic response in such a way as to create a specific and predetermined or expected magnetic response.The presence of the marker then allows extremely reliable detection over time, the presence of the marker is resistant to maintenance operations typically carried out during after-sales service, the marker can be invisible, and / or impossible to replicate.

[0011] The manufactured part may include the following characteristics, taken individually or in combination.

[0012] In one embodiment, the marker is formed, comprises, or is made of a paramagnetic material or a diamagnetic material. In another embodiment, the marker has a Relative magnetic permeability close to 1, typically between 0.9 and 1.1, between 0.95 and 1.05, or between 0.98 and 1.02. In one embodiment, the marker is formed, comprises, or is made of one or more non-magnetic materials, such as copper, aluminum, non-magnetic stainless steel, silicon, or plastic. In this embodiment, the marker does not have its own signature and / or its own response to exposure to a predetermined, time-varying magnetic field, but its presence is intended to measurably modify the response of the manufactured part. In particular, it is not the marker's own signature and / or its own response to exposure to the predetermined, time-varying magnetic field that is measured, but its presence is intended to measurably modify the response of the manufactured part.

[0013] In one embodiment, the marker is formed, comprises, or is made of an electrically conductive material. In another embodiment, the marker has a high conductivity, for example, σ > 10 3 or o > 10 4 S / m. According to one embodiment, the marker is formed, comprises, or is made of a material such as copper, aluminum.

[0014] In one embodiment, the marker is formed, comprises, or is made of a material that is weakly or not at all conductive of electricity. In another embodiment, the marker has a low conductivity, for example, σ < 10⁻¹⁰ 3 or o < 10' 4 S / m. According to one embodiment, the marker is formed, comprises, or is made up of a material such as glass, ceramic, plastic, a metal oxide such as alumina, undoped silicon.

[0015] According to one embodiment, the marker is formed, comprises, or is made of a material that may be: - doped, to be electrically conductive and exhibit a high conductivity θ, for example θ > 10 3 or o > 10 4 S / m, or - weakly doped, to be a poor conductor of electricity and exhibit a relatively low conductivity θ, for example θ < 10 or θ < 10' 2 S / m. - undoped, to remain weakly or not at all conductive of electricity and to exhibit a low conductivity, for example, θ < 10' 3 or o < 10' 4 S / m. Thus, the same component, depending on its doping, may or may not conduct electricity and modify in a targeted way the response of the marked manufactured part.

[0016] In one embodiment, the marker is not on the surface of the object. In other words, the marker is not visible or accessible from the outside. In particular, the marker is not a component affixed to an external surface of the manufactured part.

[0017] In one embodiment, the marker is not an RFID tag. In one embodiment, the marker does not include an electrical / electronic circuit. In one embodiment, the marker does not include a communication unit.

[0018] According to one embodiment, the marker provides the possibility of distinguishing the magnetic response, during or following exposure to a time-varying magnetic field, of a manufactured part equipped with the marker from the magnetic response of a manufactured part not equipped with the marker but having, for example, the same visual appearance and / or the same external dimensions, and / or the same mass, and / or the same technical characteristics as the manufactured part equipped with the marker.

[0019] In one embodiment, the marker is formed by a single component or a single specific part of the manufactured part. In one embodiment, the marker has a mass of less than 5%, preferably less than 2%, preferably less than 1% of the mass of the manufactured part. In one embodiment, the marker presents a volume of less than 5%, preferably less than 2%, preferably less than 1% of the volume of the manufactured part.

[0020] According to one embodiment, the marker forms at least part of the electrically conductive component.

[0021] In one embodiment, the marker is an electrically insulating component arranged between two electrically conductive components. In another embodiment, the marker is an insulating component or a component forming insulation within the manufactured part. In another embodiment, the marker is an insulating component or a component forming insulation and arranged between two electrically conductive parts of the manufactured part. In one embodiment, the marker has a very low conductivity (σ (S / m)) (virtually zero, less than 10⁻¹⁰). 3 S / m, preferably less than 10' 6 S / m, preferably less than 10' 10S / m) and / or a very high resistivity p (Qm) (greater than 10 6 Qm, preferably greater than 10 9 Qm, preferably greater than 10 12In one embodiment, the marker is an insulating or insulating component formed by a film or a surface treatment. In another embodiment, the marker is an insulating or insulating component sandwiched between two parts of the manufactured part, for example, electrically conductive parts. In other words, the marker is an insulating or insulating component arranged within the manufactured part to compartmentalize or modify a part or set of electrically conductive parts. In one embodiment, the marking consists of adding an insulating part (electrical insulator) between two conductive parts or adding an insulating surface treatment between contacting parts. This allows for modification of the current flow and therefore the signature during, or in response to, exposure to a varying magnetic field.In one embodiment, the marker is an electrically insulating component deposited on the surface of a functional or structural component of the manufactured part. In another embodiment, the marker is a... An electrically insulating component deposited by a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, or an atomic thin film (ALD) process. For example, the marker is a thin alumina film, with a thickness that can be approximately 5 nm, approximately 10 nm, and / or on the order of a tenth of a micron or on the order of a micron.

[0022] In one embodiment, the marker is a layered compound with a plurality of layers, each having a specific electrical conductivity or magnetic permeability, preferably different from that(s) of the other layers. In another embodiment, the marker formed by a layered compound comprises at least one electrically insulating layer arranged between two electrically conductive layers.

[0023] In one embodiment, the marker is a magnet and / or a component that exhibits remanent magnetization. This allows the signature to be modified during, or in response to, exposure to the varying magnetic field.

[0024] In one embodiment, the marker is included in a functional component of the manufactured part, such as a housing, chassis, component of an internal mechanism, external cover, or accessory of the manufactured part. Thus, there is no need to add a specific component: the marker is directly integrated into an existing component of the manufactured part that provides a particular function.

[0025] In general, the functional component provides at least one primary function in the manufactured part, for example an assembly, sealing, display, motion transmission, energy storage, decoration function...

[0026] In one embodiment, the marker also forms a visual marking. An engraving that removes a mass can be considered. A specific type of material can be used to produce a specific magnetic response. One could consider marking with an ink containing a compound that reacts to exposure to a time-varying magnetic field. For example, one could choose an ink with a compound that provides a specific magnetic response, and then plan to write some characters of a word with this ink and other characters of the word with an ink that does not react, or reacts differently.

[0027] In one embodiment, the marker is a recess formed in the functional component. This may include a cavity (open or closed), a hole (through, closed, etc.), or one or more pores. In one embodiment, the recess has a characteristic dimension (diameter, depth, length, width) greater than 0.05 mm, preferably greater than 0.1 mm, preferably greater than 0.25 mm, preferably greater than 0.5 mm, preferably greater than 0.75 mm, preferably greater than 1 mm, and / or less than 2 mm, preferably less than 1.75 mm, preferably less than 1.5 mm, preferably less than 1.25 mm, preferably less than 1 mm, preferably less than 0.75 mm.

[0028] In one embodiment, the marker is an insert formed within the functional component. In this embodiment, the marker is an insert, that is to say, an added component that is different / distinct from the component on or in which it is embedded, particularly in terms of material. In one embodiment, the insert has a characteristic dimension (diameter, depth, length, width, overall dimension) greater than 0.05 mm, preferably greater than 0.1 mm, preferably greater than 0.25 mm, preferably greater than 0.5 mm, preferably greater than 0.75 mm, preferably greater than 1 mm, and / or less than 2 mm, preferably less than 1.75 mm, preferably less than 1.5 mm, preferably less than 1.25 mm, preferably less than 1 mm, preferably less than 0.75 mm.

[0029] In one embodiment, the marker forms a specific and / or non-functional component of the manufactured part. In this embodiment, the marker is an added component that is different from / distinct from the components of the manufactured part. In this embodiment, the marker forms a specific and / or non-functional component of the manufactured part whose sole function is to produce a specific and predetermined magnetic response.

[0030] In one embodiment, the marker is a specific and / or non-functional component attached to a functional component of the manufactured part, such as a housing, chassis, component of an internal mechanism, external cover, accessory of the manufactured part, or a decorative element inside or outside the manufactured part. A surface coating, surface treatment, or film applied to a functional component of the manufactured part may be provided. A pin or screw with no assembly function may also be provided. Alternatively, a marker may be provided that forms a raised or continuous component of a functional component of the manufactured part.In one embodiment, the marker can be a physical element distinct from the rest of the part, a marking, a local modification of the material, a doping agent, an additional layer (deposited by PVD, for example), or a geometric modification of the part to obtain a specific response. In another embodiment, it is possible to substitute one element of a group with another element possessing different properties to provide a specific magnetic response, but with an appearance identical to the other elements of the group. For example, one could choose one of the screws from the manufactured part.

[0031] The term "manufactured part" encompasses any type of item that can be made by hand or by machine. This includes everyday products such as electronic devices (telephones, activity trackers), packaging, domestic or household appliances, industrial components, components of mass-produced industries (automotive, electronics, lighting, food and its packaging), safety components (personal protective equipment, medicines and their packaging, health equipment).

[0032] In one embodiment, the marker is formed by a modification, for example a local one, of the material of a component of the manufactured part. This modification, for example a local one, is formed by a localized laser treatment, and / or a localized ion implantation, and / or a localized deposition of a layer followed by a diffusion heat treatment, and / or a localized carburizing / nitriding / oxidizing treatment, and / or combinations thereof. In other words, the marker is a functional or structural component of the manufactured part whose physical or material characteristic has been modified, either globally or locally. It should be noted that, in one embodiment, this modification does not affect the dimensions of the functional or structural component of the manufactured part.It can be noted that, according to one embodiment, this modification does not affect the external appearance of the functional or structural component of the manufactured part.

[0033] According to the embodiment described above, local modification of the material is carried out to alter the electrical and / or magnetic properties of a component of the manufactured part, for example, by inducing a phase change, a modification of the crystalline structure, or a modification of the chemical composition. Thus, the magnetic response of the manufactured part equipped with the marker will differ from that of the same manufactured part without the marker, due to the imposed change in the electrical and / or magnetic properties of a component of the manufactured part.

[0034] According to one embodiment: - the functional component is formed with a first material having at least one predetermined magnetic characteristic or one predetermined electrical characteristic, - The marker is formed with a second material having at least one second predetermined magnetic characteristic or a second predetermined electrical characteristic, different respectively from the first predetermined magnetic characteristic or the first predetermined electrical characteristic. Thus, the difference in magnetic or electrical properties is intended to generate a specific and predetermined measurable magnetic response, allowing the presence of the marker to be determined.

[0035] According to one embodiment: - the functional component is formed with a first material having at least a first predetermined magnetic permeability or a first predetermined electrical conductivity, - the marker is formed with a second material having at least a second predetermined magnetic permeability or a second predetermined electrical conductivity, different by at least 50% respectively from the first predetermined magnetic permeability or the first predetermined electrical conductivity.

[0036] According to one embodiment, the marker: - is metallic, and / or - is a metallic portion of a component of the manufactured part that has undergone a predetermined surface treatment or heat treatment, or a local modification of the material, and / or - includes an electrical coil, and / or - exhibits a Curie temperature between 250 K and 400 K.

[0037] For example, one might plan to apply a specific heat treatment to an entire component of the manufactured part. For example, one Annealing between 500°C and 1200°C may be performed on a component containing a material such as FeCo, FeNi, or FeSi, which will significantly and permanently alter the magnetic properties of this component at room temperature. The component in question becomes a marker once it has undergone this heat treatment and remains geometrically identical in every respect to the same component that has not undergone heat treatment.

[0038] For example, a specific electrical coil can be provided for marking, in addition to an electrical coil of an electric motor, for example.

[0039] For example, one could consider making the marker with a magnetocaloric material, such as gadolinium, which has a magnetic behavior that changes significantly with temperature. Below a temperature point defined by the material's physical properties (the Curie point), it behaves like a ferromagnetic material, meaning it easily conducts and channels magnetic field lines. Above the Curie temperature, the material behaves paramagnetically, allowing field lines to pass through without influencing them, like air. The Curie point of gadolinium is approximately 20°C. With a marker made of this material, the magnetic response will differ depending on whether the measurement is taken at 10°C or 30°C. In other words, depending on the specific embodiment, the marker exhibits magnetic permeability or electrical conductivity that varies with temperature.Thus, it is possible to predict how the magnetic response of the manufactured part can be modified in a particular way depending on the temperature.

[0040] A "metallic / non-metallic" or "electrically conductive / non-electrically conductive" association can be established between the marker and a specific component of the manufactured part bearing the marker. For example, one of the bearing component and the One component could be made of an electrically conductive material, and the other of the carrier component and the marker could be made of a non-conductive material (such as a ceramic). Alternatively, one component could be made of a metallic material to house the carrier component and the marker, and the other of a non-metallic material to house the carrier component and the marker (such as a ceramic). For example, a ceramic part could house a metallic marker, or vice versa.

[0041] In one embodiment, the manufactured part comprises a plurality of markers, each arranged to modify the given magnetic response of the manufactured part, in order to provide the marked manufactured part with a specific and predetermined magnetic response. In other words, one can provide coding of the manufactured part or local marking.

[0042] According to one embodiment, at least two markers are formed in different materials, so that each specifically modifies the given magnetic response of the manufactured part, in order to provide the marked manufactured part with a specific and predetermined magnetic response.

[0043] According to one embodiment, at least two markers are arranged at specific and different positions on the manufactured part, so that each one modifies the given magnetic response of the manufactured part in a specific and local way, in order to provide the marked manufactured part with at least two specific, predetermined and local magnetic responses.

[0044] According to one embodiment, the plurality of markers is arranged in the manufactured part so as to provide authentication coding with the specific and predetermined magnetic response.

[0045] According to one embodiment, a method for controlling a manufactured part can be provided, comprising at least one marker arranged to modify the given magnetic response of the part. manufactured, the control method includes a control phase with the steps consisting of: - to place the manufactured part, or at least a part of the manufactured part, in a predetermined relative position with respect to at least one source of magnetic field and / or with respect to at least one magnetic field measuring device, - exposing the manufactured part, or at least a portion of the manufactured part, to at least one predetermined and time-varying magnetic field generated by the magnetic field source, - to measure, using at least one magnetic field measuring device, at least one characteristic of the magnetic field in the vicinity of the manufactured part exposed to the predetermined magnetic field, which varies over time, - to deduce a magnetic response of the manufactured part from the measured characteristic of the magnetic field in the vicinity of the manufactured part, - compare the magnetic response of the manufactured part to a reference magnetic response.

[0046] According to the implementation described above, the control method includes a step of exposing the manufactured part to at least one predetermined magnetic field that varies over time. The applicant was surprised to find that such exposure to varying magnetic fields, particularly low-amplitude varying magnetic fields, did not disrupt the operation of the manufactured part, even though it is electronic equipment. Furthermore, measuring at least one characteristic of the magnetic field in the vicinity of the manufactured part containing the marker allows for the deduction of a response from the manufactured part that can be compared to a reference magnetic response. The manufactured part containing the marker can thus be controlled, measured, or authenticated, in particular by: - verifying / checking for similarity in the response of the manufactured part including the marker with a reference magnetic response, and / or - measuring a difference in the response of the manufactured part including the marker with the reference magnetic response, - comparing the response of the manufactured part including the marker with templates built around the reference magnetic response... Thus, the manufactured part including the marker can be checked, measured or authenticated quickly, without affecting its operation, and without necessarily having to disassemble it.

[0047] More generally, a method for inspecting a manufactured part can be provided, comprising at least one marker arranged to modify the given magnetic response of the manufactured part, or a marker arranged to modify the given magnetic response of the manufactured part, the inspection method comprising an inspection phase with the steps of: - place the manufactured part including the marker, or the marker of the manufactured part, at a predetermined relative position with respect to at least one magnetic field source and / or with respect to at least one magnetic field measuring device, - expose the manufactured part including the marker, or the marker of the manufactured part, to at least one predetermined and time-varying magnetic field generated by the magnetic field source, - to measure, using at least one magnetic field measuring device, at least one characteristic of the magnetic field in the vicinity of the manufactured part including the marker, or of the marker of the manufactured part, exposed to the predetermined magnetic field which varies over time, - to deduce a magnetic response of the manufactured part including the marker, or of the marker of the manufactured part, from the measured characteristic of the magnetic field in the vicinity of the manufactured part, or of the component of the manufactured part, - compare the magnetic response of the manufactured part including the marker, or the marker of the manufactured part, to a magnetic reference response.

[0048] In particular, the invention may relate to a method for inspecting a manufactured part, which may include at least one marker arranged to modify the given magnetic response of the manufactured part, the inspection method comprising the steps of: - to place the manufactured part, or at least a part of the manufactured part, in a predetermined relative position with respect to at least one source of magnetic field and / or with respect to at least one magnetic field measuring device, - exposing the manufactured part, or at least a portion of the manufactured part, to at least one predetermined and time-varying magnetic field generated by the magnetic field source, - to measure, using at least one magnetic field measuring device, at least one characteristic of the magnetic field in the vicinity of the manufactured part exposed to the predetermined magnetic field, which varies over time, - to deduce a magnetic response of the manufactured part from the measured characteristic of the magnetic field in the vicinity of the manufactured part, - compare the magnetic response of the manufactured part to a reference magnetic response to verify / control if the manufactured part includes the marker.

[0049] According to one embodiment, during the stage of exposing the manufactured part to the predetermined and time-varying magnetic field, at least: - an amplitude, and / or - a frequency, and / or - an orientation, and / or - a spatial gradient, The magnetic field generated by the magnetic field source is modified or variable over time. As seen above, exposing a manufactured part containing a marker to such a time-varying magnetic field is not detrimental to the operation of the manufactured part.

[0050] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined and time-varying magnetic field, the frequency of the predetermined magnetic field is within a frequency range from 10 Hz to 10 7 Hz.

[0051] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined magnetic field that varies over time, the amplitude of the predetermined magnetic field is modified over time to obtain a powerful magnetic field, preferably according to a sinusoidal function.

[0052] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined magnetic field that varies over time, the amplitude of the predetermined magnetic field is within a range of values ​​from 0 T to 5.10 -1T and preferably within a value range from 0 T to 5.10 -3 T, and preferably within a value range from 0 T to 10' 3 T.

[0053] In one embodiment, during the step of exposing the manufactured part containing a marker to a predetermined magnetic field that varies over time, a relative movement is imposed between the manufactured part containing the marker and the magnetic field source. This relative movement allows the manufactured part containing the marker to be exposed to a varying magnetic field, even if the magnetic field source generates a constant or fixed magnetic field.

[0054] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined and time-varying magnetic field, the orientation of the predetermined magnetic field varies by at least 10°, and preferably by at least 30°, relative to an initial orientation of the predetermined magnetic field. It is possible to generate a rotating magnetic field, even over a limited angular sector, for example, less than 360°.

[0055] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined and time-varying magnetic field, the orientation of the predetermined magnetic field varies cyclically, and for example the orientation of the predetermined magnetic field varies to impose a rotating magnetic field, for example at a frequency of at least 50 revolutions per second, and preferably at least 5 x 10⁻¹². 2 revolutions per second.

[0056] According to one embodiment, the step of exposing the manufactured part comprising a marker to a predetermined magnetic field that varies over time includes a step of electrically supplying at least one electric coil, or even at least two electric coils simultaneously or with a time offset (if, for example, the manufactured part comprises at least two distinct markers).

[0057] According to one embodiment, the step of measuring at least one characteristic of the magnetic field in the vicinity of the manufactured part comprising a marker includes the measurement: - of an amplitude and / or orientation of the magnetic field, and / or - of a current induced in a coil, and / or - of a voltage induced in a coil.

[0058] According to one embodiment, the step of measuring at least one characteristic of the magnetic field in the vicinity of the manufactured part comprising a marker is carried out: - by at least one magnetic field sensor, and / or - by at least one electrical coil, called the receiving coil, preferably by at least one coil of the magnetic field source, called the transmitting and receiving coil, used to generate the predetermined magnetic field, which varies over time. The use of a transmitting and receiving coil allows for a simple measuring device with a limited number of components.

[0059] According to one embodiment, the step of deducing the magnetic response of the manufactured part comprising a marker includes: - a comparison between a value of a magnetic field characteristic measured without the manufactured part, and a value of the magnetic field characteristic measured in the vicinity of the manufactured part including a marker, and / or - a calculation of the phase shift between the generated magnetic field and a value of the magnetic field characteristic measured in the vicinity of the manufactured part including a marker, - an analysis phase involving the construction of a Bode plot, and / or a Nyquist plot, and / or a Fourier series decomposition. Placing the manufactured part in a varying magnetic field alters the distribution and amplitude of the magnetic field within and around the manufactured part containing a marker. This resulting modified magnetic field is measured and analyzed to deduce the magnetic response of the manufactured part containing the marker.

[0060] According to one embodiment, the control method includes an initial baseline phase with the steps of: - place a manufactured reference part (including a reference marker) at the predetermined relative position with respect to said at least one magnetic field source and with respect to said at least one magnetic field measuring device, - expose the reference manufactured part to the said at least one field predetermined and time-varying magnetic field generated by the magnetic field source, - measure at least one characteristic of the magnetic field in the vicinity of the manufactured reference part exposed to the predetermined magnetic field, which varies over time, - to deduce a magnetic response of the reference manufactured part from the measured characteristic of the magnetic field in the vicinity of the manufactured part, - record the magnetic response of the reference manufactured part.

[0061] According to one embodiment, the step of placing the manufactured part including a marker at a predetermined relative position with respect to at least one magnetic field source and with respect to at least one magnetic field measuring device includes a step of placing the manufactured part including a marker in a fixture and / or clamping the manufactured part including a marker in a fixture, and / or mechanically stopping the manufactured part including a marker on or in a fixture.In one embodiment, the steps of placing the manufactured part including a marker in a fixture and / or clamping the manufactured part including a marker in a fixture, and / or mechanically abutting the manufactured part including a marker against or within a fixture are performed by bringing the manufactured part including a marker into contact or against a positioning portion of said fixture with at least one magnetic field source. Thus, the relative position between the manufactured part including a marker and the magnetic field source and / or the measuring device is reproducible, reliable, and robust.

[0062] According to one embodiment, the step of placing the manufactured part comprising a marker at a predetermined relative position with respect to at least one magnetic field source and The measurement process, relative to at least one magnetic field measuring device, includes a step of placing the manufactured part containing a marker within 10 mm, preferably within 7 mm, preferably within 5 mm, preferably within 2 mm, preferably within 1 mm, of at least one magnetic field source and / or at least one magnetic field measuring device, and most preferably, the manufactured part containing a marker is placed in contact with said at least one magnetic field source and / or with said at least one magnetic field measuring device. Thus, the manufactured part containing a marker is well exposed to the magnetic field (as is the marker), and / or is located close to the measuring device, which ensures reliable measurements with a good signal-to-noise ratio.

[0063] According to one embodiment, the step of exposing the manufactured part including a marker to a predetermined and time-varying magnetic field generated by the magnetic field source, and / or the step of measuring at least one characteristic of the magnetic field in the vicinity of the manufactured part including a marker exposed to the predetermined and time-varying magnetic field are carried out at least partially simultaneously.

[0064] According to one embodiment, the step of exposing the manufactured part including a marker to a predetermined and time-varying magnetic field generated by the magnetic field source, and the step of measuring at least one characteristic of the magnetic field in the vicinity of the manufactured part including a marker exposed to the predetermined and time-varying magnetic field are carried out over a period of less than 2 minutes, preferably less than 1 minute, preferably less than 10 s, preferably less than 7 s, preferably less than 5 s, preferably less than 3 s.

[0065] According to one embodiment, the step of exposing the manufactured part comprising a marker to a predetermined and time-varying magnetic field generated by the magnetic field source includes: - a first control step consisting of exposing a first portion of the manufactured part, including for example a first marker, to a first predetermined magnetic field that varies over time, generated by the magnetic field source, - A second control step involves exposing a second portion of the manufactured part, including, for example, a second marker, to a second predetermined magnetic field that varies over time, generated by the magnetic field source. This allows for the control, measurement, and authentication of distinct parts of the same manufactured part containing one or more markers. It is even possible to reconstruct a code by placing markers at predetermined locations on the manufactured part. The presence of a marker can represent a "1" in a binary code, and its absence can represent a "0".

[0066] In one embodiment, the inspection method is a control method implemented after a specific manufacturing operation of the manufactured part, including a marker. An assembly operation can be used to verify that all components are present and / or arranged in the correct position. Alternatively, a "new" inspection can be performed immediately after manufacturing to record the result for comparison during subsequent maintenance visits, even several years later.

[0067] In one embodiment, the control method forms a method for authenticating the manufactured part, which includes a marker, implemented, for example, during or prior to a maintenance operation. In another embodiment, the authentication method includes an initial phase of establishing a signature before delivery. including the steps, implemented for example during a final manufacturing inspection, consisting of: - place the new manufactured part, including a marker, at the predetermined relative position with respect to at least one magnetic field source and with respect to at least one magnetic field measuring device, - expose the newly manufactured part, including a marker, to at least one predetermined and time-varying magnetic field generated by the magnetic field source, - measure at least one characteristic of the magnetic field in the vicinity of the new manufactured part, including a marker exposed to a predetermined magnetic field that varies over time, - to deduce a magnetic response of the new manufactured part including a marker from the measured characteristic of the magnetic field in the vicinity of the new manufactured part including a marker, - record the magnetic response of the new manufactured part including a marker as the reference magnetic response.

[0068] According to one embodiment, the magnetic response of the new manufactured part including a marker forms a reference signature, and / or the magnetic response of the manufactured part to be checked forms a signature of the manufactured part including a marker.

[0069] According to one embodiment, the control method includes a final phase comprising the steps of: - quantify the difference between the magnetic response of the manufactured part containing a marker and the reference magnetic response, and / or - compare with a predetermined threshold the difference between the magnetic response of the manufactured part containing a marker and the response magnetic reference, and / or - qualify the manufactured part including a controlled marker as a compliant manufactured part or as an authentic manufactured part, in particular if a difference between the magnetic response of the manufactured part including a marker and the reference magnetic response is less than a predetermined threshold and / or is acceptable.

[0070] According to one embodiment, during the exposure step of the manufactured part comprising a marker to a predetermined magnetic field that varies over time, at least: - an amplitude, and / or - a frequency, and / or - an orientation, and / or - a spatial gradient of the magnetic field generated by the magnetic field source exhibits a non-zero time derivative for at least 10 ns, preferably at least 100 ns, preferably at least 1 ps, preferably at least 100 ps, ​​preferably at least 1 ms, preferably at least 1 s, preferably at least 10 s, preferably at least 1 minute. However, it is not excluded to provide time intervals during which the magnetic field does not vary, although preferably the magnetic field varies throughout the exposure to the magnetic field.

[0071] According to one embodiment, the magnetic field source includes at least one magnet, such as a permanent magnet, and the step of exposing the manufactured part to at least one predetermined and time-varying magnetic field generated by the magnetic field source includes a step of imposing at least one relative movement between the magnetic field source and the manufactured part comprising a marker.

[0072] According to one embodiment, said at least one predetermined magnetic field that varies over time, the amplitude of which It exhibits a sinusoidal, rectangular, triangular, jump, pseudorandom binary sequence (PRBS), and / or multifrequency signal (sum of several sinusoids of different chosen frequencies). It can be noted that the electric current generating the predetermined and time-varying magnetic field also exhibits this sinusoidal, rectangular, etc., temporal shape.

[0073] According to one embodiment, the measurement can be made by gradually varying the frequency, for example, a measurement at a first frequency fi for a certain duration (a few periods), a measurement at a second frequency f2 for a certain time (a few periods), etc.

[0074] According to one embodiment, it is possible to plan to make the measurement with a multi-frequency signal (which includes a sinusoid of first frequency fi and amplitude ai, a sinusoid of second frequency f2 and amplitude a2, a sinusoid of third frequency fs and amplitude as, etc.) which allows the test to be done quickly, with a single signal which includes the different desired frequencies. Description of the figures

[0075] Other features and advantages of the present invention will become more apparent upon reading the following detailed description of embodiment(s) of the invention given by way of non-limiting example(s) and illustrated by the accompanying drawings, in which:

[0076] [fig. 1] schematically represents at a given instant field lines of a variable magnetic field generated by a transmitting coil with a first frequency;

[0077] [fig. 2] schematically represents the field lines of the variable magnetic field generated by the transmitting coil, when a manufactured part is placed near the transmitting coil;

[0078] [fig. 3] schematically represents the field lines of the variable magnetic field generated by the transmitting coil with a second frequency, when the manufactured part is always placed near the transmitting coil;

[0079] [fig. 4] schematically represents a manufactured part similar to the manufactured part in figures 2 and 3, comprising a marker intended to provide the marked manufactured part with a specific and predetermined magnetic response;

[0080] [fig. 5] represents the manufactured part comprising a marker of figure 4, installed near a source of magnetic field and a measuring device together forming a first variant of a control device to measure a magnetic response of the manufactured part to exposure to a variable magnetic field;

[0081] [fig. 6] represents the manufactured part including a marker of figure 4, installed near a second variant of a control device to measure a magnetic response of the manufactured part to exposure to a variable magnetic field;

[0082] [fig. 7] represents a variant of the manufactured part including a marker of figure 4, installed near a third variant of a control device to measure a magnetic response of the variant of the manufactured part including a marker to exposure to a varying magnetic field;

[0083] [fig. 8] represents a variant of the manufactured part in figure 7, installed near the third variant of a control device to measure a magnetic response of the variant of the manufactured part comprising a marker to exposure to a variable magnetic field;

[0084] [fig. 9] generally represents concrete implementation variants of the magnetic field source, to illustrate the manufactured part comprising a marker with a variable magnetic field;

[0085] [fig. 10] represents a graph showing magnetic responses of several manufactured parts, measured with the control method implemented by the control device in figure 5 for example;

[0086] [fig. 11] represents a graph showing an example of a variable signal that can be used when implementing this control method;

[0087] [fig. 12] represents in the upper part a graph of the magnetic responses of two manufactured parts of identical external appearance and represented in the lower part. One of the manufactured parts includes an internal housing (or inlay) with a marker made of ferromagnetic metal;

[0088] [fig. 13] represents in the upper part a graph of the magnetic responses of two manufactured parts including screws shown in the lower part. One of the manufactured parts includes so-called standard screws, and the other of the manufactured parts includes screws with a localized surface treatment to form a marker;

[0089] [Fig. 14] shows in its upper part a graph of the magnetic responses of three manufactured parts comprising internal components of the same dimensions and shown in the lower part. The first of the manufactured parts includes a first internal component with a first surface treatment, the second of the manufactured parts includes a second internal component with a second surface treatment, the third of the manufactured parts includes a third internal component with a third surface treatment.

[0090] Detailed description of implementation method(s)

[0091] Figure 1 schematically represents, at a given instant, the field lines of a varying magnetic field generated by a transmitting coil 10 with a first frequency. In the example given, the transmitting coil 10 is static, and the transmitting coil 10 is supplied with a varying electric current. Figure 1 represents the distribution of the field lines at a given instant. In the case shown, the coil is circular with a square cross-section. The model or distribution of the field lines: - is axisymmetric around the vertical axis of the coil in figure 1; - is symmetric with respect to a plane parallel to the upper or lower face of the transmitting coil 10 and which passes through the center of the transmitting coil 10. In the case of Figure 1, and for the rest of the disclosure, Figure 1 represents a transmitting coil 10 alone, but a core or a frame, for example, made of a material with high magnetic permeability (for example, a ferromagnetic material) can be provided to direct or concentrate the magnetic field lines in a particular way.

[0092] Figure 2 schematically represents the field lines of the varying magnetic field generated by the transmitting coil 10 when a manufactured part 100 (represented by dashed lines in Figure 2) is placed near the transmitting coil 10. In the example given, and as in the example in Figure 1, the transmitting coil 10 is always stationary, and it is supplied with a varying electric current (typically an alternating current, for example, a sinusoidal or square wave current). Figure 2 shows the distribution of the field lines at a given instant. It can be noted that the manufactured part 100 significantly alters the distribution of field lines compared to the case in Figure 1.

[0093] As is well known, a magnetic field, whose amplitude varies over time, induces electrical voltages in any conductive material placed within that field (typically a component of the part). (manufactured, shown in Figure 2 or 3). These induced voltages cause the appearance of induced current loops, called eddy currents, the direction of which is given by Lenz's law. According to Lenz's law, the direction of the induced current is such that, through its effects, it opposes the cause that gave rise to it. Eddy currents therefore flow in a direction creating a field opposite to the field that gave rise to them, which modifies the distribution of the magnetic field.

[0094] We can therefore observe in Figure 2 that the magnetic field, generated by the transmitting coil 10 at the first frequency, exhibits field lines that are modified compared to the field lines in Figure 1. In particular, we can note the presence of field lines within the manufactured part 100 itself, at a first depth P1 relative to the bottom of the manufactured part 100.

[0095] Figure 3 schematically represents the field lines of the variable magnetic field generated by the transmitting coil 10 with a second frequency, when the manufactured part 100 (represented in dotted lines) is always placed near the transmitting coil 10.

[0096] In the example given in Figure 3, the transmitting coil 10 is supplied with a variable electric current (an alternating current such as a sinusoidal or square wave current) having a second frequency, and the second frequency is higher than the first frequency used to illustrate Figures 1 and 2.

[0097] By comparing figures 2 and 3, we can note a significant change in the distribution of field lines within the manufactured part 100 itself in figure 3. In particular, we can note in figure 3 field lines at a second depth P2 relative to the bottom of the manufactured part 100, the second depth P2 being less than the first depth P1.

[0098] In summary, and as shown in Figures 1 to 3, the field lines are modified by the mere presence of the manufactured part 100. According to the present invention, the manufactured part 100 can be equipped with a marker designed to provide the marked manufactured part with a specific and predetermined magnetic response. In other words, and in particular, with reference to Figure 4, which forms a schematic diagram, the manufactured part 100 includes a marker 110 which, by its presence, makes it possible to measure a specific, and at the very least measurable, magnetic response that differs from that of the same manufactured part without the marker 110.

[0099] Manufactured item 100 can be any type of part made by hand or by machine. In Figures 2 to 7, manufactured item 100 is very schematic and has a general circular or cylindrical shape with a bottom (a base) and a top. It could be packaging (a round box designed to hold medicine, food products, etc.), an electronic item (a pacemaker, a speaker, etc.), a mechanical part (a pulley, a brake disc, etc.), a fashion accessory (a silver pen, a gold belt buckle, etc.), a decorative object (a vase or a metal sculpture), a piece of furniture (silver cutlery, knives, brass chandeliers, etc.), an item of clothing, etc. [000100] Marker 110 can be formed by: - all or part of the outer wall of the manufactured part (the bottom, the lid, ...), - all or part of an internal component of the manufactured part 100, such as for example a component of a mechanism, an assembly screw... According to one embodiment, the marker 110 may be the only electrically conductive component of the manufactured part 100. [000101] The marker 110 can typically include at least one metal part, and it is possible to provide for the marker to be formed at least in part 110 with an alloy such as steel, stainless steel (for example according to grade 1.4404 or AISI 316L, typically non-magnetic), or grade 1.4539 (or AISI 904L, typically non-magnetic), or brass, or an alloy of copper (typically non-magnetic), titanium (typically non-magnetic), gold (typically non-magnetic), platinum (typically non-magnetic)... [000102] The marker 110 can be formed by coating a material on a component of the manufactured part 100. A local modification of the material of a component of the manufactured part 100 can be provided, for example, localized laser treatment and / or localized ion implantation and / or localized deposition of a layer followed by diffusion heat treatment and / or local carburizing / nitriding / oxidizing treatment (or combinations thereof), in order to modify the electrical and / or magnetic properties, for example by inducing a phase change, a modification of the crystalline structure, a modification of the chemical composition... [000103] The marker 110 can be formed by a component of the manufactured part 100 that has undergone a specific heat treatment. For example, thermal annealing carried out between 500°C and 1200°C on a component comprising FeCo and / or FeNi, and / or FeSi, can make it possible to form a marker that will impose a specific magnetic response on the manufactured part 100. [000104] Marker 110 can be formed in a material whose magnetic response varies with temperature. For example, marker 110 can be formed from a material whose Curie temperature is between 250 K and 400 K. Below a temperature point defined by the physical properties of the material (Curie point), the material behaves like a ferromagnetic material, that is, it conducts and channels magnetic field lines easily. For temperatures above the Curie temperature, the material behaves in a Being paramagnetic, it allows field lines to pass through without influencing them, like air. Gadolinium could be used, for example. [000105] The marker 110 can be formed by an electrical coil or part of an electrical coil. [000106] The marker 110 can alternatively be a recess in material or a non-electrically conductive insert, formed or embedded in a component normally present in the manufactured part and electrically conductive. The presence of the marker (typically occupying a volume normally occupied by an electrically conductive material) will then significantly modify the magnetic response of the manufactured part 100 to exposure to the varying magnetic field. [000107] The marker 110 can just as easily be an electrically insulating component inserted within an electrically conductive component or between two electrically conductive components. It could be made of plastic, an insulating film, an insulating oxide layer, etc. The presence of the marker 110 will then significantly modify the paths of the induced electric currents and therefore the magnetic response of the manufactured component 100 to exposure to the varying magnetic field. [000108] The marker 110 can finally be a magnetic part, that is to say a permanent magnet glued or arranged in the manufactured part 100 to modify its magnetic response. [000109] Figure 5 represents the manufactured part 100 of Figure 4, including the marker 110, installed near a magnetic field source 21 and a measuring device 23 together forming a first variant of a control device 20 for measuring a magnetic response of the manufactured part 100 including the marker 110 to exposure to a variable magnetic field. [000110] In detail, the control device 20 comprises: - the magnetic field source 21 formed by an electrical coil that one can describe it as a transmitting coil, - the measuring device 23 formed by an electrical coil which can be described as a receiving coil - a fixture 25 forming an imprint to receive the manufactured part 100 including the marker 110 without play in order to guarantee a reliable and repeatable relative positioning between the manufactured part 100 including the marker 110 and the magnetic field source 21 and / or the measuring device 23, - optional clamping means 26, here with an articulated arm which presses the manufactured part 100 including the marker 110 against the magnetic field source 21, - a data acquisition and control system 24, including in particular: • at least one voltage measuring device V, connected to the magnetic field source 21 and / or the measuring device 23, • at least one current measuring device A, connected to the magnetic field source 21 and / or the measuring device 23, • at least one control unit UC (which may include an electronic control unit, a memory unit, a computing unit, a current generator, a voltage generator, internal means for measuring voltage or current, a communication unit ...) connected to the magnetic field source 21 and / or the measuring device 23, the voltage measuring device V, the current measuring device A, • a display device, which can also form a human-machine interface to receive control instructions from an operator. [000111] The control unit UC is intended to generate and impose an electric current in the magnetic field source 21 so as to expose the manufactured part 100 comprising the marker 110 to a time-varying magnetic field whose frequency The predetermined magnetic field is within a frequency range from 10 Hz to 10 7 Hz. [000112] If, for example, the marker 110 is arranged on the surface (or near the surface) of the manufactured part, it can be predicted that the frequency of the predetermined magnetic field is within a frequency range from 5.10 2 Hz to 10 7 Hz, preferably 10 4 Hz to 10 7 Hz, to get closer to the case illustrated in figure 3. [000113] If, for example, the marker 110 is arranged far from the surface (or close to the center) of the manufactured part, it can be predicted that the frequency of the predetermined magnetic field is within a frequency range from 10 Hz to 10 4 Hz and preferably in a frequency range from 5.10 2 Hz at 5.10 3 Hz, to get closer to the case illustrated in figure 2. [000114] It is also possible to vary the frequency of the predetermined magnetic field, so as to cover a whole range of frequencies within a general frequency range from 10 Hz to 10 7 Hz. Thus, the entire manufactured part 100, including marker 110, will be inspected / measured / authenticated. Typically, a multi-frequency signal can be applied with a current whose time waveform is the sum of sinusoids of various frequencies fi, f2, fs, etc., judiciously chosen. Typically, the frequency of the predetermined magnetic field can be varied according to a pseudorandom binary sequence (PRBS). [000115] By way of example, Figure 11 shows an example of a signal that can be used to vary the frequency of the predetermined magnetic field. Figure 11 shows an example of an electric current that can be imposed in the magnetic field source 21. In Figure 11, the signal has an amplitude A varying, for example, from 0% to 100% of full scale, and a frequency that varies with time. The amplitude A of the signal in Figure 11 is generally square or rectangular in shape. slots. We can predict a multi-frequency signal that can be decomposed into a Fourier series, for example. [000116] Generally, the control unit UC is designed to generate and impose an electric current in the magnetic field source 21 so as to expose the manufactured part 100, including the marker 110, to a time-varying magnetic field whose predetermined magnetic field amplitude is within a range of 0 T to 5.10 -1 T and preferably within a value range from 0 T to 5.10 -3 T, and preferably within a value range from 0 T to 10' 3 T. [000117] In the case of Figure 5, the magnetic field source 21 and the measuring device 23 are fixed to an electronic board substrate 22. The magnetic field source 21 and the measuring device 23 can be formed with printed circuits on the electronic board substrate 22. For example, loops can be formed or printed directly onto the electronic board substrate 22. Circular loops or loops of different shapes can be provided, depending on the geometry of the manufactured part 100 and / or the marker 110. [000118] The control device 20 of Figure 5 therefore comprises a fixture 25 receiving and positioning: - on the one hand, the magnetic field source 21, the measuring device 23 and the electronic board substrate 22, On the other hand, the manufactured part 100, including the marker 110, is positioned via an imprint or a counter-form, so that the relative position between the manufactured part 100, including the marker 110, the magnetic field source 21, and the measuring device 23 is reliable and repeatable. Clamping means 26 can be provided to press or hold the manufactured part 100, including the marker 110, in contact with the magnetic field source 21, for example. Thus, there is no air gap between the manufactured part 100, including the marker 110 and the magnetic field source 21, so that the manufactured part 100 including the marker 110 is perfectly exposed to the variable magnetic field generated by the magnetic field source 21. [000119] The fixture 25, the clamping means 26, and the electronic board substrate 22 can be made of materials that are non-conductive and / or "transparent" to magnetic fields, i.e., with a relative magnetic permeability close to 1, and / or non-magnetic materials. The fixture 25 and clamping means 26 can be made of Teflon or plastic, for example. [000120] In the case of Figure 5, the magnetic field source 21 and the measuring device 23 are formed by separate coils. The magnetic field generated at each point in the vicinity of the magnetic field source 21 is variable. According to Faraday's law of electromagnetic induction, if the magnetic flux coupled with a loop or coil (the measuring device 23) varies with time, a voltage is induced across the coil forming the measuring device 23. It follows that by placing the measuring device 23 in the vicinity of the magnetic field source 21 and the manufactured part 100 containing the marker 110 (the manufactured part to be checked / measured / authenticated), an induced voltage is generated by the varying field across the coil of the measuring device 23. This induced voltage can serve as a basis for deducing the magnetic response of the manufactured part 100 containing the marker 110. [000121] To perform an inspection of a particular manufactured part 100 (including a marker 110), it is possible to generate with the magnetic field source 21 the same magnetic field varying over time, and it is possible to measure iteratively the induced voltage: - without any manufactured parts 100, - with a 100% manufactured reference part (including a marker) 110 reference); - with a manufactured part 100 to be checked / measured / authenticated and including the marker 110. [000122] These different induced voltages can be recorded, and a comparison can then be planned: - directly the induced voltage with the reference manufactured part 100 and the induced voltage with the manufactured part 100 including the marker 110 to be checked, - on the one hand the induced voltage without any manufactured part 100 and the induced voltage with the reference manufactured part 100 and on the other hand the induced voltage without any manufactured part 100 and the induced voltage with the manufactured part 100 including the marker 110 to be checked. [000123] We can also foresee defining a frequency response as being the ratio between the induced voltage measured across the terminals of the coil (which is a receiving coil) of the measuring device 23 and the voltage applied across the terminals of the coil (which is a transmitting coil) of the magnetic field source 21, without current in the measuring coil. [000124] The analysis of these transfer functions for the manufactured part 100, including the marker 110 to be inspected, allows the use of mathematical tools. Representations can be made in a Bode or Nyquist plot, which also allows for the comparison of measured manufactured parts. The analysis of non-sinusoidal periodic signals can be performed using a Fourier series decomposition. [000125] Thus, by comparing the induced voltages according to the different options, it is possible to quantify a difference between a magnetic response of the manufactured part 100 including the marker 110 to be checked and a magnetic response of the reference manufactured part 100. It is then possible to check / measure / authenticate the manufactured part 100 including the marker 110 to be checked based on the identified difference (on can verify that the difference is less than a threshold, one can check for the absence or presence of a particular parameter or shape on the response curve... ). [000126] It can be noted that in the example of Figure 5 the receiving coil of the measuring device 23 is arranged under the transmitting coil of the magnetic field source 21. However, other arrangements or locations can be chosen, both for the coil of the measuring device 23 and for the coil of the magnetic field source 21. [000127] Several coils can also be provided for the measuring device 23 and / or several coils for the magnetic field source 21. One or more coils of the magnetic field source 21 can be supplied simultaneously or sequentially, and an induced voltage across one or more coils of the measuring device 23 can be measured simultaneously or sequentially. [000128] Figure 6 shows the manufactured part 100 of Figure 4, including the marker 110, installed near a second variant of a control device 20 for measuring the magnetic response of the manufactured part 100, including the marker 110, to exposure to a varying magnetic field. In particular, the manufactured part 100, including the marker 110, is housed within the second variant of a control device 20, and the remainder of the control device 20 (similar to that shown in Figure 5) is not shown. In the example of the second embodiment in Figure 6, the manufactured part 100, including the marker 110, will essentially be exposed to field lines passing through it and normal to its bottom or top surface. [000129] In the example of the second embodiment shown in Figure 6, it can be noted that the control device 20 comprises only one electrical coil, which can be described as a transmitting-receiving coil. Indeed, it is possible to use a single coil, and the measurement of the Current and / or voltage can provide the information necessary for control / measurement / authentication. [000130] In the case of a current measurement, one can quantify the amplitudes and / or phase shifts of the current (more precisely the current intensity) during tests: - without any manufactured parts 100, - with a manufactured part 100 of reference and including a marker 110 of reference; - with a manufactured part 100 to be checked and including a marker 110. [000131] It is possible to do the same with the voltage across the coil of the control device 20. [000132] Alternatively or in addition, the impedance of the transmitting-receiving coil of the control device 20 can be measured. The impedance of a coil is defined in complex notation by: U = Z . I with U the voltage across the coil and I the current flowing through it. We can also recall that any coil can be characterized electrically by a resistance R and by a reactance X (a function of the current frequency and the inductance L of the coil) forming the complex impedance Z. [000133] In the presence of electrically conductive material in a manufactured part to be inspected, the field variation and induced currents cause a change in impedance compared to the case without the manufactured part. In particular, the resistance R takes into account the internal Joule losses of the coil and also the eddy current losses in the manufactured part to be inspected. The inductance L is related to the distribution of the field lines, which are modified by the presence of eddy currents in the manufactured part. The presence of a marker that modifies Specifically and / or locally the resistance R of the manufactured part or at least one of its components can provide the marked manufactured part with a specific and predetermined magnetic response. [000134] The different quantities are then a function of the frequency f of the varying magnetic field: - resistance: R(f), - inductance: L(f), - reactance: X(f), - impedance magnitude: Z(f), - Impedance argument: cp(f). Depending on the material and dimensions of the components of the manufactured part and the marker 110, these functions differ. They can therefore be used as a "signature" or "magnetic response" to characterize an equipped manufactured part. In some cases, it may be advantageous to define functions that include measurements with the manufactured part without the marker, with the manufactured part equipped with the marker 110, and without the manufactured part to facilitate mathematical processing and graphical representation. [000135] Figure 7 shows a variant of the manufactured part 100 of Figure 4, installed in a third variant of a control device for measuring the magnetic response of the variant of the manufactured part 100 of Figure 4 to exposure to a varying magnetic field. The remainder of the control device (similar to that in Figure 5) is not shown. [000136] In Figure 7, it can be seen that the manufactured part 100 includes two markers 110, each housed on the periphery of the manufactured part 100. A marker 110 can be installed at different locations on the manufactured part 100. If the marker 110 is present at a location, the value 1 can be assigned, and if it is absent, the value can be assigned. assign the value 0. In the case of figure 7, going from left to right and top to bottom, we would have a code 11. [000137] In the case of the third variant of the measuring device shown in Figure 7, the control device 20 comprises only a single electrical coil surrounding the manufactured part 100. The latter will essentially be exposed to field lines passing through it and parallel to its bottom or top surface. As shown in Figure 7, measurements can be taken by placing the coil of the measuring device 20 at the level of a top portion, so as to properly expose the markers 110 to the time-varying magnetic field. It is even possible to use a coil that surrounds only a portion of the manufactured part 100, for example, if the manufactured part 100 has protruding parts. [000138] Figure 8 shows an alternative embodiment in which the manufactured part is an electronic device, and more particularly a mobile phone. Two specific markers 110 can be housed at predetermined locations, and when the coil of the measuring device 20 passes near the two markers 110, a specific magnetic response can be measured. The measuring device 20 of Figure 5, Figure 6, or Figure 7 can, of course, be used interchangeably for the mobile phone shown in Figure 8. [000139] Figure 9 generally represents variant embodiments of the magnetic field source 21, for exposing the manufactured part to a variable magnetic field. [000140] Figure 9, on the left, shows a single-phase system with a single diametral coil 21 A and a ferromagnetic cylinder 29. It is understood that with a single coil 21 A, a variable magnetic field can be generated, typically by supplying the coil 21 A with a variable current, for example, a sinusoidal current, a square wave current, or more generally, a variable alternating current. If the The current is alternating and has a period during which the current reverses. The field lines will have an amplitude that varies over each half-period, and their direction will reverse between the first and second half-periods. The field is charged and its direction reverses, but its orientation does not change. [000141] Figure 9, on the right, shows a three-phase system with three diametrical coils 21 A, 21 B, 21 C. In this case, it is possible to supply the three coils 21 A, 21 B, 21 C with a three-phase current system, of period T, the magnetic field rotates with respect to the coils 21 A, 21 B, 21 C. The amplitude of the field is constant over time. The field rotates at a speed of f revolutions per second. At 1000 Hz, the field therefore rotates at 1000 revolutions per second. [000142] With reference to Figures 5, 6, 7, 8 and 9, it is understood that numerous constructions and arrangement possibilities are conceivable both for generating the variable magnetic field and for measuring it once the manufactured part 100, including the marker 110, is placed near the magnetic field source. These include: - a transmitting coil, arranged at a certain relative position with respect to the manufactured part 100 comprising the marker 110, - several transmitting coils, placed at various relative positions with the manufactured part 100 comprising the marker 110, - a receiving coil, arranged at a certain relative position with respect to the manufactured part 100 comprising the marker 110, - several receiving reels, placed at various relative positions with the manufactured part 100 comprising the marker 110, - a transmitting-receiving coil, arranged at a certain relative position with respect to the manufactured part 100 comprising the marker 110, - several transmitting-receiving coils, placed at various relative positions with the manufactured part 100, - but we can also provide for one or more magnetic field sensors, placed at various relative positions with the manufactured part 100 including marker 110. Regarding the aforementioned magnetic field sensor, one can foresee a Hall effect sensor, a magnetoresistive sensor, a giant magnetoresistance, a SQUID type magnetometer (“Superconducting Quantum Interference Device”). [000143] Alternatively, a relative displacement can also be imposed between the manufactured part 100, including the marker 110, and the magnetic field source 21. In this case, two superimposed transmitting-receiving coils can be used to perform a differential measurement. The two transmitting-receiving coils are powered identically at a given frequency to generate the varying magnetic field and produce induced currents in the manufactured part. If the manufactured part 100, including the marker 110, is moved along the axis of the transmitting-receiving coils, the resistance and reactance of the two transmitting-receiving coils change depending on the axial position of the manufactured part, including the marker 110, taking into account the geometry and material of the manufactured part.The measurement of resistances and / or inductances, reactances and / or impedances can then define the magnetic response which allows to control / measure / authenticate the manufactured part 100 including the marker 110. [000144] Figure 10 schematically represents a graph of the magnetic responses of several manufactured parts, measured using the testing method according to the invention. Figure 10 shows normalized impedance curves reconstructed after testing eleven manufactured parts. Each manufactured part was exposed to the same magnetic field, which varied over time, with a frequency ranging from 10 Hz to 10 5 Hz, with a control device comprising a single transmitting-receiving coil, the impedance of which has been measured simultaneously with exposure to the variable magnetic field of the manufactured part. [000145] The tested manufactured parts were all of the same model, but ten manufactured parts from family A included a marker, and an eleventh manufactured part from family B was a manufactured part without a marker, despite an external visual appearance entirely similar to the manufactured parts equipped with a marker. Specifically, the material of some of the ten manufactured parts from family A was a first grade of stainless steel (the marker), and the material of the case of the eleventh manufactured part from family B was a second grade of stainless steel. [000146] It can be noted that Figure 10 shows all the curves of the manufactured parts of family A in a very close group, whereas the curve of the eleventh manufactured part of family B is very different. It appears that the control method, consisting of exposing a manufactured part to a variable magnetic field to measure a magnetic response, can be used to reliably control / measure / authenticate the manufactured part containing a marker. [000147] Depending on the implementation of the marker and its location, it may be necessary or practical to dismantle part of the manufactured part, for example, remove a cover, or a housing. [000148] Figure 12 shows in its upper part a graph representing the magnetic responses of two manufactured parts 100Ref and 100, which have an identical external appearance and are shown in the lower part of Figure 12. The manufactured part 100Ref in the lower part of Figure 12 is a metal part, for example, a link in a chain, made entirely of stainless steel, for example, non-magnetic. The manufactured part 100 in the lower part of Figure 12 is a metal part having the same external appearance and shape as the manufactured part 100Ref. However, the manufactured part 100 is made of stainless steel with an interior housing (or inlay) with a marker 110 for example in ferromagnetic metal which modifies the properties of electrical conductivity and circulation of eddy currents when exposed to a variable magnetic field. [000149] The manufactured part 100Ref and the manufactured part 100 have identical external dimensions, on the order of tens of millimeters, and a volume on the order of 50 mm³ 3 at 150 mm 3 The marker 110 of the manufactured part 100 is an insert housed or embedded in the manufactured part 100 and has external dimensions on the order of a millimeter, and a volume on the order of 1 mm³. 3 at 5 mm 3 Marker 110 may include iron, steel and may be ferromagnetic. [000150] It can be noted in the upper part of figure 12 that the magnetic responses are notably different, with for example at 11000 Hz a clearly measurable difference which makes it possible to distinguish the two pieces from each other without any doubt, the two pieces having the same external appearance and predominantly the same material. [000151] Figure 13 shows in its upper part a graph of the magnetic responses of two manufactured parts comprising screws shown in the lower part of Figure 13. One of the manufactured parts comprises standard screws (Ref), and the other comprises screws with a localized surface treatment forming a marker 110. In the example shown in Figure 13, the Ref screws and the screws forming a marker 110 have the same appearance and external dimensions. These are M2 screws, used to fasten metal components in a remote control housing, for example. The screws forming a marker 110 have received a localized surface treatment, in this case carburizing or carburizing, enriching the external surface with carbon, thus forming a marker 110. The carburizing or carburizing applied to the screws forming the marker 110 consists of enriching the steel of these screws with carbon to a depth of a few tenths of a millimeter.The hardness can range from 50 HRC to 63 HRC. with such carburizing or carburizing. In this example, the screw heads were treated, but treatment can be considered for any other surface, or even the entire surface. [000152] It can be noted in the upper part of figure 13 that the magnetic responses of the manufactured parts including the screws Ref or the screws forming a marker 110 are markedly different, with for example at 15000 Hz a clearly measurable difference which makes it possible to distinguish one from the other without any doubt the two parts, which nevertheless have the same appearance and / or external dimensions. [000153] Figure 14 shows in its upper part a graph of the magnetic responses of three manufactured parts comprising an internal component of the same dimensions and material, shown in the lower part. The first of the manufactured parts comprises a first internal component with a first surface treatment forming a first marker 110-1, the second of the manufactured parts comprises a second internal component with a second surface treatment forming a second marker 110-2, the third of the manufactured parts comprises a third internal component with a third surface treatment forming a third marker 110-3. [000154] The manufactured parts may be, for example, remote controls with metallic components, and the components shown in the lower part of Figure 14 are typically metallic mounting plates for other components. These components shown in the lower part of Figure 14 may be made of brass, steel, gold, platinum, or nickel-phosphorus alloy, and have identical external dimensions, on the order of tens of millimeters. [000155] The first internal component received a first surface treatment forming a first marker 110-1, here an electrically conductive coating composed of rhodium (0.25 µm thick), nickel (0.25 µm thick), and gold (0.5 µm thick). The second internal component has The third internal component received a second surface treatment forming a second marker 110-2, in this case a 0.6 µm thick nickel-phosphorus alloy (NiP12) coating that is electrically conductive. The third internal component received a third surface treatment forming a third marker 110-3, in this case a 10 nm thick alumina (Al2O3) coating that is electrically insulating. [000156] It can be noted in the upper part of Figure 14 that the magnetic responses of the manufactured parts, each comprising the first marker 110-1, or the second marker 110-2, or even the third marker 110-3, are markedly different, for example at approximately 3.10 4 Hz-4.10 4 Hz or even at 5.10 6 Hz, clearly measurable differences that allow us to distinguish without a doubt the three manufactured parts, which include an internal component that nevertheless has the same appearance and / or dimensions. Industrial application [000157] A control method according to the present invention, and its manufacture, are capable of industrial application. [000158] It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the different embodiments of the invention described in this description without departing from the scope of the invention.

Claims

DEMANDS [Claim 1] Manufactured part (100), comprising at least one electrically conductive component providing the manufactured part (100) with a given magnetic response to exposure to a predetermined and time-varying magnetic field, characterized in that the manufactured part (100) comprises at least one marker (110) arranged to modify the given magnetic response of the manufactured part (100), in order to provide the marked manufactured part (100) with a specific and predetermined magnetic response. [Claim 2] Manufactured part (100) according to claim 1, wherein the marker (110) is included in a functional component of the manufactured part (100). [Claim 3] Manufactured part (100) according to claim 2, wherein the marker (110) is a recess formed in the functional component. [Claim 4] Manufactured part (100) according to claim 2, wherein the marker (110) is an insert formed in the functional component. [Claim 5] Manufactured part (100) according to claim 1, wherein the marker (110) forms a specific and / or non-functional component of the manufactured part (100). [Claim 6] Manufactured part (100) according to claim 5, wherein the marker (110) is a specific and / or non-functional component attached to a functional component of the manufactured part (100). [Claim 7] Manufactured part (100) according to any one of claims 1 to 6, wherein the marker (110) is formed by a modification, for example a local modification, of the material of a component of the manufactured part (100), the modification, for example a local modification, being formed for example by a localized laser treatment for example, and / or localized ion implantation for example and / or localized deposition of a layer followed by diffusion heat treatment and / or local treatment for example of carburization / nitriding / oxidation and / or combinations thereof. [Claim 8] Manufactured part (100) according to any one of claims 2 to 4 or according to claim 6 or 7, wherein: - the functional component is formed with a first material having at least one predetermined magnetic characteristic or one predetermined electrical characteristic, - the marker (110) is formed with a second material having at least one second predetermined magnetic characteristic or a second predetermined electrical characteristic, different respectively from the first predetermined magnetic characteristic or the first predetermined electrical characteristic. [Claim 9] Manufactured part (100) according to any one of claims 2 to 4 or according to claims 6 to 8, wherein: - the functional component is formed with a first material having at least a first predetermined magnetic permeability or a first predetermined electrical conductivity, - the marker (110) is formed with a second material having at least a second predetermined magnetic permeability or a second predetermined electrical conductivity, different by at least 50% respectively from the first predetermined magnetic permeability or the first predetermined electrical conductivity. [Claim 10] Manufactured part (100) according to any one of claims 1 to 9, wherein the marker (110): - is metallic, and / or - is a metallic portion of a component of the manufactured part (100) that has undergone a predetermined surface treatment or heat treatment, or a local modification of the material, and / or - includes an electrical coil, and / or - exhibits a Curie temperature between 250 K and 400 K. [Claim 11] Manufactured part (100) according to any one of claims 1 to 9, comprising a plurality of markers (110) each arranged to modify the given magnetic response of the manufactured part (100), in order to provide the marked manufactured part (100) with a specific and predetermined magnetic response. [Claim 12] Manufactured part (100) according to claim 10, wherein at least two markers (110) are formed in different materials, so that each specifically modifies the given magnetic response of the manufactured part (100), in order to provide the marked manufactured part (100) with a specific and predetermined magnetic response. [Claim 13] Manufactured part (100) according to claim 10 or 11, wherein at least two markers (110) are arranged at specific and different positions of the manufactured part (100), so that each one specifically and locally modifies the given magnetic response of the manufactured part (100), in order to provide the marked manufactured part (100) with at least two specific, predetermined, and local magnetic responses. [Claim 14] Manufactured part (100) according to any one of claims 10 to 12, wherein the plurality of markers (110) is arranged in the manufactured part (100) so as to provide authentication coding with the specific and predetermined magnetic response.

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