EP2786372A1 - Vibration sensor device for musical instruments - Google Patents

Vibration sensor device for musical instruments

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Publication number
EP2786372A1
EP2786372A1 EP12801619.3A EP12801619A EP2786372A1 EP 2786372 A1 EP2786372 A1 EP 2786372A1 EP 12801619 A EP12801619 A EP 12801619A EP 2786372 A1 EP2786372 A1 EP 2786372A1
Authority
EP
European Patent Office
Prior art keywords
measuring
coil
excitation
coils
wound around
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP12801619.3A
Other languages
German (de)
French (fr)
Inventor
Jean-Pierre Perin Ambroise
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP2786372A1 publication Critical patent/EP2786372A1/en
Withdrawn legal-status Critical Current

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Classifications

    • GPHYSICS
    • G10MUSICAL INSTRUMENTS; ACOUSTICS
    • G10HELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H3/00Instruments in which the tones are generated by electromechanical means
    • G10H3/12Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument
    • G10H3/14Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument using mechanically actuated vibrators with pick-up means
    • G10H3/18Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument using mechanically actuated vibrators with pick-up means using a string, e.g. electric guitar
    • G10H3/181Details of pick-up assemblies
    • GPHYSICS
    • G10MUSICAL INSTRUMENTS; ACOUSTICS
    • G10HELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H3/00Instruments in which the tones are generated by electromechanical means
    • G10H3/12Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument
    • G10H3/14Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument using mechanically actuated vibrators with pick-up means
    • G10H3/18Instruments in which the tones are generated by electromechanical means using mechanical resonant generators, e.g. strings or percussive instruments, the tones of which are picked up by electromechanical transducers, the electrical signals being further manipulated or amplified and subsequently converted to sound by a loudspeaker or equivalent instrument using mechanically actuated vibrators with pick-up means using a string, e.g. electric guitar
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/22Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils
    • G01D5/225Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the mutual induction between the two coils
    • G01D5/2275Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the mutual induction between the two coils by a movable non-ferromagnetic conductive element
    • GPHYSICS
    • G10MUSICAL INSTRUMENTS; ACOUSTICS
    • G10HELECTROPHONIC MUSICAL INSTRUMENTS; INSTRUMENTS IN WHICH THE TONES ARE GENERATED BY ELECTROMECHANICAL MEANS OR ELECTRONIC GENERATORS, OR IN WHICH THE TONES ARE SYNTHESISED FROM A DATA STORE
    • G10H2220/00Input/output interfacing specifically adapted for electrophonic musical tools or instruments
    • G10H2220/461Transducers, i.e. details, positioning or use of assemblies to detect and convert mechanical vibrations or mechanical strains into an electrical signal, e.g. audio, trigger or control signal
    • G10H2220/505Dual coil electrodynamic string transducer, e.g. for humbucking, to cancel out parasitic magnetic fields

Definitions

  • the present invention relates to a vibration sensor device for musical instruments. It also relates to a sound generation system implementing the device.
  • the field of the invention is more particularly but in a non-limiting manner that of the sound of stringed musical instruments.
  • the sound of stringed musical instruments is generally performed by means of devices that directly measure the vibration of the strings.
  • devices based on an inductive measurement principle are placed near the ropes. They include a permanent magnet that generates a static magnetic field, and an inductance coil traversed by a magnetic flux due to the magnet. The magnetic field is disturbed by the presence of the metal cord, whose vibrations cause by electromagnetic induction, and / or variation of the magnetic circuit, flux variations in the inductor. The measurement of these flux variations is performed by measuring the induced voltage across the coil. It allows to obtain a measurement of the vibration of the rope used then to generate a sound.
  • An object of the present invention is to provide a sound collecting device, in particular for measuring the vibrations of musical instrument strings, which is capable of producing a metrologically accurate measurement of the vibration, in particular from the point of view of view of spectral content, dynamics and distortion.
  • Another object of the present invention is to provide a sound collecting device with a sensitivity adapted to different spatial modes of vibration of the strings.
  • Another object of the present invention is to propose a sound collection device that is easy to integrate on existing instruments, which is not very sensitive to environmental disturbances, and with a spatially confined measurement zone.
  • a sensor device for measuring a displacement and / or vibration of at least one object of interest, in particular for musical instruments which comprises:
  • excitation inductance coils electrically connected to at least one electrical excitation source and capable of generating magnetic excitation fluxes
  • At least one measurement inductance coil electrically connected to electrical measurement means able to measure induced electrical signals
  • a magnetic circuit magnetically connecting the excitation and measurement coils, and comprising a measurement zone in which the presence of objects of interest affects magnetic fluxes originating from excitation coils and passing through said coil (s) measuring, and
  • excitation coils arranged in such a way as to generate, in the absence of any object of interest in the measuring zone, magnetic fluxes which substantially compensate in the at least one measuring coil.
  • the measurement zone may comprise in particular an air gap, or a free space in the magnetic circuit.
  • the device according to the invention can comprise:
  • a measuring coil a first excitation coil strongly coupled to said measuring coil so that the flux generated by said first excitation coil in the measurement coil is not affected by the presence of an object in the measuring zone, and a second excitation coil more weakly coupled to said measuring coil so that the flux generated by said second excitation coil in the measuring coil is strongly affected by the presence of an object in the measuring area;
  • excitation and measurement coils each made in one of the following forms: a single winding, a plurality of partial windings distributed over the magnetic circuit.
  • the magnetic circuit may comprise a magnetic material, that is to say a material with a magnetic permeability greater than one, such as for example a ferromagnetic material or a ferrimagnetic material.
  • the magnetic circuit may comprise a portion consisting at least partially of magnetic material, of substantially U-shaped section with a base and two substantially parallel branches, the measuring zone extending substantially beyond and between the ends of said branches opposite said base.
  • the branches, or the branches and the base, may comprise a magnetic material.
  • the device according to the invention may further comprise:
  • a measuring coil wound around the base a first excitation coil wound around said base, and a second excitation coil with two partial windings wound respectively around the two branches so as to generate in the measuring zone. respectively a flow leaving one branch and a flow entering the other branch;
  • the magnetic circuit may comprise:
  • a part made at least partially of magnetic material of substantially E-shaped section with a base, a central branch and two substantially parallel lateral branches, the measurement zone extending substantially beyond and between the ends of said branches; opposite to said base,
  • the coils can be made according to a planar geometry, in particular with techniques for producing printed circuits.
  • the magnetic circuit may comprise:
  • a part made at least partially of magnetic material of substantially cylindrical shape and of substantially "E" -shaped diametrical section with a base, a central stud and an outer ring, the measurement zone extending substantially the opposite of said base,
  • a device for capturing the sounds of a string musical instrument which is adapted to be placed on said instrument for measuring the vibration of at least one string.
  • the device may include:
  • a substantially cylindrical magnetic circuit defining a measurement zone for measuring the vibration of a string of the instrument without being significantly affected by the vibration of adjacent strings;
  • a magnetic circuit of substantially elongated shape defining a measurement zone making it possible to measure the vibration of a plurality of strings of the instrument.
  • a sound generation system comprising a vibration measuring device according to the invention, and electronic and calculation means for generating sounds from the measured vibrations.
  • the sound generation system according to the invention can be configured so as to be able to generate sounds reproducing the sounds of a given microphone and / or the assembly of a certain instrument and microphone.
  • the invention makes it possible to make a number of innovations, particularly as regards its use for capturing instrument sounds.
  • FIG. 1 illustrates a stringed instrument in the form of an electric guitar equipped with devices according to the invention
  • FIG. 2 illustrates a device profile view according to the invention
  • FIG. 3 (a) illustrates a first embodiment of winding mode in which the device according to the invention is substantially sensitive to vertical displacements as illustrated in FIG. 3 (b),
  • FIG. 4 (a) illustrates a second variant of winding mode in which the device according to the invention is substantially sensitive to horizontal displacements as illustrated in FIG. 4 (b),
  • FIG. 5 illustrates a device electrical diagram according to the invention
  • FIG. 6 illustrates a device embodiment according to the invention adapted to measuring the movement of a rope, with in FIG. 6 (a) the device of FIG. 6 (b) presented without shielding,
  • FIG. 7 illustrates a top view of the device according to the invention according to an embodiment adapted to the measurement of displacement of a plurality of ropes simultaneously.
  • the device according to the invention or sensor 2 is designed so as to be fixed on the body of a guitar 1, under the ropes 4. It can in particular be made so that it can be fixed on existing instruments 1 in locations provided for sound sensors of the prior art.
  • the instrument 1 comprises a connector 3 which makes it possible to connect the sensor or sensors 2 to an electronics and / or an external sound system.
  • the senor 2 comprises a magnetic circuit consisting essentially of an element 10 made of magnetic or ferromagnetic material such as ferrite.
  • This element 10 has a substantially U-shaped or "H" shaped profile, with a base 16 and substantially parallel branches 15 which rise substantially perpendicularly to this base.
  • the device further comprises inductance coils 11, 12, 13 made with an electrically conductive element such as copper wire wound around the ferromagnetic element 10, directly or on a support. These coils are connected together and / or to a control electronics by connecting wires 14. They comprise a measuring coil 13 wound around the base 16, and two excitation coils 11 and 12 respectively wound around the branches 15 and the base 16 of the magnetic circuit.
  • the excitation coils 11, 12 and measuring coils 13 are electromagnetically coupled by the magnetic circuit and in particular by the ferromagnetic element 10.
  • the excitation coils 11, 12 When the excitation coils 11, 12 are excited by an alternating signal, they generate magnetic fluxes of which at least part passes through the measuring coil, and generates a voltage induced at its terminals.
  • the structure of the magnetic circuit and the coils is designed so as to define a measurement zone 17 which extends substantially beyond the branches 15 of the magnetic circuit.
  • An electrically conductive object (such as an instrument string 4) present in this measurement zone 17 disrupts the magnetic flux passing through the measuring coil 13, which makes it possible to detect it.
  • This measurement zone 17 constitutes an air gap of the magnetic circuit, which makes it possible to confine it spatially. Indeed, the magnetic field lines present in the magnetic circuit are little influenced by objects in the vicinity of the ferromagnetic element 10, with the exception of the measurement zone 17. This confinement effect is important to limit the disturbances of the environment, facilitate the integration of the sensor 2 on an instrument 1, and limit the effects of crosstalk between neighboring ropes 4.
  • FIGS. 3 and 4 show two variants of embodiments of the windings which make it possible to produce sensors 2 that are essentially sensitive, respectively, to modes of vibration of the vertical ropes 4 (that is to say substantially parallel to the branches 15) or horizontal (that is to say substantially parallel to the base 16).
  • the senor 1 comprises: a measuring coil 13 R placed around the base 16 of the magnetic circuit 10,
  • an excitation coil 11 El consisting of two partial coils 11a, 11b respectively placed around the branches 15 of the magnetic circuit 10.
  • the excitation coils 11a, 11b and 12 are connected in series and connected to an alternating excitation source Ve.
  • the excitation coil 12 is strongly coupled to the measuring coil
  • the measuring coil 13 in the sense that most of the magnetic flux 31 that it generates also passes through the measuring coil 13.
  • the flux 31 generated by the excitation coil 12 and coupled in the measuring coil 13 is not or little affected by the presence of an object 4 in the measuring zone 17.
  • the two partial coils 11a and 11b are wound in opposite directions, so as to respectively generate a flux 30 exiting in the measuring zone 17 (for example at the level of the coil 11b) and a stream 30 entering the branch 15 ( for example at the level of the coil l ia).
  • the excitation coils 11a, 11b and 12 are wound so that their respective flows 30, 31 through the measuring coil 13 are in phase opposition.
  • their inductances are adjusted so that, taking into account the coupling, the resulting flux in the measuring coil 13 is almost zero, that is to say that the fluxes 30, 31 compensate for themselves at least partially at level of the measuring coil 13.
  • the excitation coil 11a, 11b Since the excitation coil 11a, 11b is less well coupled to the measuring coil 13 than the excitation coil 12 (or has larger leakage fluxes), it comprises a greater total number of turns.
  • this arrangement makes it possible to measure the movement 32 of an object 4 along the vertical axis Oz (substantially parallel to the branches 15) independently of the variations of position of this same object 4 in the plane on the perpendicular axes Ox and Oy.
  • the magnetic fields generated by the excitation coils 11 and 12 are in phase opposition and compensate at least partially through the measuring coil 13 in the absence of object 4.
  • only the field of the coil 11 is significantly modified by the presence of the object 4.
  • the magnetic fields generated by the partial excitation coils 11a, 11b of the coil 11 compensate each other when the object 4 describes a movement along the axis Ox and therefore do not give rise to a variation of the measured voltage Vs in the measuring coil 13.
  • the sensor 1 comprises:
  • the excitation coils 42 and 43 are connected in series and connected to an alternative excitation source Ve.
  • the excitation frequency may be of the order of 1 MHz.
  • the two excitation coils 42, 43 are coupled substantially identically to the measuring coil 13.
  • the two excitation coils 42, 43 are wound in opposite directions, so as to generate in the measurement zone 17 flows 40, 41 of opposite orientation.
  • the excitation coils 42, 43 are wound so that their respective fluxes 40, 41 through the measuring coil 13 are also in phase opposition, and that the resulting flux in the measuring coil 13 is close to zero. i.e., the fluxes 40, 41 compensate each other at least partially at the level of the measuring coil 13. As illustrated in FIG. 4b, this arrangement makes it possible to measure the movement 44 of an object 4 along the horizontal axis Ox (substantially parallel to the base 16) independently of the variations of position of this same object 4 along the perpendicular axes Oz and Oy.
  • the magnetic fields generated by the excitation coils 42 and 43 compensate each other when the object of interest 4 describes a movement along the vertical axis Oz and does not give rise to a variation of the voltage Vs in the measuring coil 13.
  • the object 4 is substantially centered with respect to the two excitation coils 42, 43 and that its movement 44 is smaller than the distance separating the center of the excitation coils 42 and 43. Indeed, the rejection the movement of the object 4 along the axis Oz is even greater when the object 4 is centered between the excitation coils 42 and 43.
  • the target 4 such as an instrument chord
  • the target 4 is of a dimension considered as infinite along the axis Oy with respect to the dimensions of the sensor 1, no measurement is made on this axis. .
  • Figure 5 shows a chain of acquisition and processing of measurement signals.
  • excitation part which comprises an oscillator 52 and an amplifier 53, for generating a high frequency excitation signal Ve, of the order of 1 MHz.
  • the amplifier 53 supplies excitation coils 50, 51 connected in series and arranged in particular according to the embodiments of FIGS. 3 and 4.
  • the processing chain comprises an amplifier 54, a rectifier 55 and a low-pass filter 56. It makes it possible to straighten and filter the induced voltage Vr measured across the measuring coil 13 to extract the envelope, representative of the vibration of the object 4.
  • the demodulated signal can then be processed by sound systems, digital or analog sound generation or synthesis.
  • the number of turns of the measuring coil 13 is maximized to obtain a maximum voltage Vs and a bandwidth covering at least the audible spectrum (up to 20 kHz).
  • the senor is more sensitive when the voltage Vs in the absence of object 4 is not equal to zero but rather to a low value corresponding to the case where the contribution of E2 in R and greater than that of El in R.
  • the senor 2 can be made in a substantially cylindrical shape with a diameter of the order of 5 mm.
  • the configuration of the excitation coils 11, 12 may be according to the embodiment of FIG. 3 or that of FIG. 4.
  • the sensor 1 is further provided with a shield 60 on its periphery which improves its immunity to disturbances, and the confinement of the measurement zone 17.
  • This embodiment makes it possible to equip an instrument 1 with sensors 2 so that each sensor 2 only measures the vibration of an individual rope 4.
  • the senor 2 can be made in a substantially elongated form, so as to have a measurement zone 17 capable of including several ropes 4 (or all the ropes 4) of an instrument 1.
  • FIG. 7 shows a view from above of a sensor 2 with a base 16 and two branches 15, a profile view of which corresponds to FIG. 2.
  • the configuration of the excitation coils 11, 12 is that of the embodiment of FIG.
  • the sensor 2 is sensitive to the vertical movement 32 along the axis Oz of the ropes 4, including when the ropes extend in the direction of the branches 15 along the axis Oy.
  • This embodiment makes it possible to equip an instrument 1 with a single, simple sensor, which provides a signal Vs representative of all the vibrations of the ropes 4 which pass through the measurement zone 17.
  • Excitation coils can be connected to the electronics in all possible ways, especially in series, in parallel, or powered by different excitation sources;
  • the demodulation of the signal representative of the vibration can be carried out by digital means, after a direct acquisition of the signal Vr. It can also be performed by a synchronous demodulator.

Abstract

The present invention relates to a sensor device (2) for measuring a movement and/or a vibration of at least one object of interest, in particular for musical instruments, said device comprising (i) at least two excitation inductance coils (11, 12) electrically connected to at least one electric excitation source, and capable of generating excitation magnetic fluxes, and (ii) at least one measuring inductance coil (13), electrically connected to electrical measuring means capable of measuring induced electrical signals, (iii) a magnetic circuit (10) magnetically connecting the excitation coils (11, 12) and measuring (13) coils, and comprising a measuring area (17) wherein the presence of objects of interest affects magnetic fluxes coming from excitation coils (11, 12) and passing through said measuring coil or coils (13), and (iv) excitation coils (11, 12) arranged in such a way as to generate, in the absence of an object of interest in the measuring area (17), magnetic fluxes which substantially cancel each other out in the at least one measuring coil (13). The invention also relates to a sound system implementing said device.

Description

« Dispositif capteur de vibrations pour instruments de musique »  "Vibration sensor device for musical instruments"
Domaine technique Technical area
La présente invention concerne un dispositif capteur de vibrations pour instruments de musique. Elle concerne aussi un système de génération de sons mettant en œuvre le dispositif.  The present invention relates to a vibration sensor device for musical instruments. It also relates to a sound generation system implementing the device.
Le domaine de l'invention est plus particulièrement mais de manière non limitative celui de la sonorisation d'instruments de musiques à cordes.  The field of the invention is more particularly but in a non-limiting manner that of the sound of stringed musical instruments.
Etat de la technique antérieure  State of the art
La sonorisation d'instruments de musique à cordes, tels que des guitares électriques ou des violons, est effectuée en général au moyen de dispositifs qui permettent de mesurer directement la vibration des cordes.  The sound of stringed musical instruments, such as electric guitars or violins, is generally performed by means of devices that directly measure the vibration of the strings.
Il existe en particulier des dispositifs basés sur un principe de mesure inductive. Ces dispositifs sont placés à proximité des cordes. Ils comprennent un aimant permanent qui génère un champ magnétique statique, et une bobine d'inductance traversée par un flux magnétique dû à l'aimant. Le champ magnétique est perturbé par la présence de la corde métallique, dont les vibrations provoquent par induction électromagnétique, et/ou variation du circuit magnétique, des variations de flux dans la bobine d'inductance. La mesure de ces variations de flux est effectuée en mesurant la tension induite aux bornes de la bobine. Elle permet d'obtenir une mesure de la vibration de la corde utilisée ensuite pour générer un son.  In particular, there are devices based on an inductive measurement principle. These devices are placed near the ropes. They include a permanent magnet that generates a static magnetic field, and an inductance coil traversed by a magnetic flux due to the magnet. The magnetic field is disturbed by the presence of the metal cord, whose vibrations cause by electromagnetic induction, and / or variation of the magnetic circuit, flux variations in the inductor. The measurement of these flux variations is performed by measuring the induced voltage across the coil. It allows to obtain a measurement of the vibration of the rope used then to generate a sound.
Ces dispositifs présentent un certain nombre d'inconvénients :  These devices have a number of disadvantages:
- Leur fonction de transfert présente en général un comportement fréquentiel de circuit résonnant avec une bande passante étroite et des non linéarités importantes. Cela affecte fortement la reproduction du son, et crée de la distorsion ;  Their transfer function generally presents a frequency behavior of resonant circuit with a narrow bandwidth and significant nonlinearities. This strongly affects the sound reproduction, and creates distortion;
- Ils présentent également des problèmes de diaphonie ou de couplage entre cordes voisines de l'instrument, qui sont également sources de bruits et de distorsion. Ces problèmes proviennent en particulier de couplages magnétiques parasites entre les circuits magnétiques de chaque corde, et de la sensibilité de ces dispositifs aux perturbations de l'environnement. On connaît de nombreuses réalisations de tels dispositifs de sonorisation, avec des géométries de circuit magnétique et des structures de bobines variées. - They also have problems of crosstalk or coupling between strings adjacent to the instrument, which are also sources of noise and distortion. These problems arise in particular parasitic magnetic couplings between the magnetic circuits of each string, and the sensitivity of these devices to environmental disturbances. Numerous embodiments of such sound reinforcement devices are known, with magnetic circuit geometries and various coil structures.
On connaît par exemple le document US 5,789,691, qui décrit un dispositif de collecte de son basé sur un aimant permanent, qui comprend un circuit magnétique avec un plot ferromagnétique en face de chaque corde, et des bobines de détection qui englobent l'ensemble des circuits magnétiques de toutes les cordes. Cela permet de réaliser des systèmes à bas coût plus faciles à interfacer.  Document US Pat. No. 5,789,691, for example, describes a sound-collecting device based on a permanent magnet, which comprises a magnetic circuit with a ferromagnetic pad opposite each string, and detection coils which encompass all the circuits. magnetic of all the strings. This allows for low cost systems that are easier to interface.
On connaît également le document US 7,989,690 de Lawing, qui décrit un dispositif de collecte de son dans lequel la mesure de vibration de chaque corde est effectuée au moyen d'une bobine particulière de forme adaptée, dans le but d'améliorer le comportement en bruit et en distorsion.  Also known is US Pat. No. 7,989,690 to Lawing, which describes a sound collection device in which the vibration measurement of each string is performed by means of a particular coil of adapted shape, in order to improve the noise behavior. and distortion.
De manière générale, les dispositifs existants de collecte de son pour instruments à cordes, du fait de leurs imperfections sur le plan métrologique, ont un effet non négligeable sur le son produit et fournissent une information appauvrie sur les modes de vibration des cordes. Ces inconvénients sont particulièrement gênants pour l'exploitation des mesures de vibration de cordes dans des systèmes électroniques de génération de son, où l'on recherche avant tout une information fidèle et complète.  In general, existing sound collection devices for stringed instruments, because of their metrological imperfections, have a significant effect on the sound produced and provide impoverished information on the vibration modes of the strings. These drawbacks are particularly troublesome for the exploitation of string vibration measurements in electronic sound generation systems, where one seeks above all a faithful and complete information.
Un objet de la présente invention est de proposer un dispositif de collecte de son, en particulier pour mesurer les vibrations de cordes d'instruments de musique, qui soit apte à produire une mesure de la vibration fidèle sur le plan métrologique, notamment du point de vue du contenu spectral, de la dynamique et de la distorsion.  An object of the present invention is to provide a sound collecting device, in particular for measuring the vibrations of musical instrument strings, which is capable of producing a metrologically accurate measurement of the vibration, in particular from the point of view of view of spectral content, dynamics and distortion.
Un autre objet de la présente invention est de proposer un dispositif de collecte de son avec une sensibilité adaptée aux différents modes spatiaux de vibration des cordes.  Another object of the present invention is to provide a sound collecting device with a sensitivity adapted to different spatial modes of vibration of the strings.
Un autre objet de la présente invention est de proposer un dispositif de collecte de son facile à intégrer sur des instruments existants, peu sensible aux perturbations de l'environnement, et avec une zone de mesure confinée spatialement.  Another object of the present invention is to propose a sound collection device that is easy to integrate on existing instruments, which is not very sensitive to environmental disturbances, and with a spatially confined measurement zone.
Exposé de l'invention Cet objectif est atteint avec un dispositif capteur pour mesurer un déplacement et/ou une vibration d'au moins un objet d'intérêt, notamment pour instruments de musique, qui comprend : Presentation of the invention This objective is achieved with a sensor device for measuring a displacement and / or vibration of at least one object of interest, in particular for musical instruments, which comprises:
- au moins deux bobines d'inductance d'excitation électriquement reliées à au moins une source électrique d'excitation, et aptes à générer des flux magnétiques d'excitation, et  at least two excitation inductance coils electrically connected to at least one electrical excitation source and capable of generating magnetic excitation fluxes, and
- au moins une bobine d'inductance de mesure, électriquement reliée à des moyens électriques de mesure aptes à mesurer des signaux électriques induits,  at least one measurement inductance coil, electrically connected to electrical measurement means able to measure induced electrical signals,
caractérisé en ce qu'il comprend en outre :  characterized in that it further comprises:
- un circuit magnétique reliant magnétiquement les bobines d'excitation et de mesure, et comprenant une zone de mesure dans laquelle la présence d'objets d'intérêt affecte des flux magnétiques issus de bobines d'excitation et traversant ladite ou lesdites bobine(s) de mesure, et  a magnetic circuit magnetically connecting the excitation and measurement coils, and comprising a measurement zone in which the presence of objects of interest affects magnetic fluxes originating from excitation coils and passing through said coil (s) measuring, and
- des bobines d'excitation disposées de telle sorte à générer, en l'absence d'objet d'intérêt dans la zone de mesure, des flux magnétiques qui se compensent sensiblement dans l'au moins une bobine de mesure.  excitation coils arranged in such a way as to generate, in the absence of any object of interest in the measuring zone, magnetic fluxes which substantially compensate in the at least one measuring coil.
La zone de mesure peut comprendre notamment un entrefer, ou un espace libre dans le circuit magnétique.  The measurement zone may comprise in particular an air gap, or a free space in the magnetic circuit.
Suivant des modes de réalisation, le dispositif selon l'invention peut comprendre :  According to embodiments, the device according to the invention can comprise:
- une bobine de mesure, une première bobine d'excitation fortement couplée à ladite bobine de mesure de telle sorte que le flux généré par ladite première bobine d'excitation dans la bobine de mesure soit peu affecté par la présence d'un objet dans la zone de mesure, et une seconde bobine d'excitation plus faiblement couplée à ladite bobine de mesure de telle sorte que le flux généré par ladite seconde bobine d'excitation dans la bobine de mesure soit fortement affecté par la présence d'un objet dans la zone de mesure ;  a measuring coil, a first excitation coil strongly coupled to said measuring coil so that the flux generated by said first excitation coil in the measurement coil is not affected by the presence of an object in the measuring zone, and a second excitation coil more weakly coupled to said measuring coil so that the flux generated by said second excitation coil in the measuring coil is strongly affected by the presence of an object in the measuring area;
- une bobine de mesure et deux bobines d'excitation couplées à ladite bobine de mesure de telle sorte que le flux généré par lesdites bobines d'excitation dans la bobine de mesure soit affecté de manière sensiblement identique par la présence d'un objet dans la zone de mesure ; - des bobines d'excitation et de mesure réalisées, chacune, selon l'une des formes suivantes : un bobinage unique, une pluralité de bobinages partiels répartis sur le circuit magnétique. - a measuring coil and two excitation coils coupled to said measuring coil so that the flux generated by said excitation coils in the measuring coil is affected substantially identically by the presence of an object in the measuring area; excitation and measurement coils each made in one of the following forms: a single winding, a plurality of partial windings distributed over the magnetic circuit.
Suivant des modes de réalisation, le circuit magnétique peut comprendre un matériau magnétique, c'est-à-dire un matériau avec une perméabilité magnétique supérieure à un, tel que par exemple un matériau ferromagnétique ou un matériau ferrimagnétique.  According to embodiments, the magnetic circuit may comprise a magnetic material, that is to say a material with a magnetic permeability greater than one, such as for example a ferromagnetic material or a ferrimagnetic material.
Suivant des modes de réalisation, le circuit magnétique peut comprendre une partie constituée au moins partiellement de matériau magnétique, de section sensiblement en forme de « U » avec une base et deux branches sensiblement parallèles, la zone de mesure s'étendant sensiblement au delà et entre les extrémités desdites branches à l'opposé de ladite base.  According to embodiments, the magnetic circuit may comprise a portion consisting at least partially of magnetic material, of substantially U-shaped section with a base and two substantially parallel branches, the measuring zone extending substantially beyond and between the ends of said branches opposite said base.
Les branches, ou les branches et la base, peuvent comprendre un matériau magnétique.  The branches, or the branches and the base, may comprise a magnetic material.
Le dispositif selon l'invention peut en outre comprendre :  The device according to the invention may further comprise:
- une bobine de mesure bobinée autour de la base, une première bobine d'excitation bobinée autour de ladite base, et une seconde bobine d'excitation avec deux bobinages partiels bobinés respectivement autour des deux branches de telle sorte à générer dans la zone de mesure respectivement un flux sortant d'une branche et un flux entrant dans l'autre branche ;  a measuring coil wound around the base, a first excitation coil wound around said base, and a second excitation coil with two partial windings wound respectively around the two branches so as to generate in the measuring zone. respectively a flow leaving one branch and a flow entering the other branch;
- une bobine de mesure bobinée autour de la base, et deux bobines d'excitation bobinées respectivement autour des deux branches de telle sorte à générer dans la zone de mesure des flux sortant desdites branches ;  - a measuring coil wound around the base, and two excitation coils respectively wound around the two branches so as to generate in the measurement zone flows out of said branches;
- une bobine de mesure bobinée autour d'une branche, et deux bobines d'excitation bobinées respectivement autour des deux branches de telle sorte à générer dans la zone de mesure des flux sortant desdites branches.  - A measuring coil wound around a branch, and two excitation coils respectively wound around the two branches so as to generate in the measurement zone flows out of said branches.
Suivant d'autres modes de réalisation, le circuit magnétique peut comprendre :  According to other embodiments, the magnetic circuit may comprise:
- une partie constituée au moins partiellement de matériau magnétique, de section sensiblement en forme de « E » avec une base, une branche centrale et deux branches latérales sensiblement parallèles, la zone de mesure s'étendant sensiblement au delà et entre les extrémités desdites branches à l'opposé de ladite base,  a part made at least partially of magnetic material, of substantially E-shaped section with a base, a central branch and two substantially parallel lateral branches, the measurement zone extending substantially beyond and between the ends of said branches; opposite to said base,
- une bobine de mesure bobinée autour de ladite branche centrale, - une première bobine d'excitation bobinée autour de ladite branche centrale, et a measuring coil wound around said central branch, a first excitation coil wound around said central branch, and
- une seconde bobine d'excitation avec deux bobinages partiels bobinés respectivement autour des deux branches latérales.  a second excitation coil with two partial windings wound respectively around the two lateral branches.
Les bobines peuvent être réalisées suivant une géométrie planaire, en particulier avec des techniques de réalisation de circuits imprimés.  The coils can be made according to a planar geometry, in particular with techniques for producing printed circuits.
Suivant encore d'autres modes de réalisation, le circuit magnétique peut comprendre :  According to still other embodiments, the magnetic circuit may comprise:
- une partie constituée au moins partiellement de matériau magnétique, de forme sensiblement cylindrique et de section diamétrale sensiblement en forme de « E » avec une base, un plot central et une couronne externe, la zone de mesure s'étendant sensiblement à l'opposé de ladite base,  a part made at least partially of magnetic material, of substantially cylindrical shape and of substantially "E" -shaped diametrical section with a base, a central stud and an outer ring, the measurement zone extending substantially the opposite of said base,
- une bobine de mesure bobinée autour dudit plot central,  a measuring coil wound around said central stud,
- une première bobine d'excitation bobinée autour dudit plot central, et - une seconde bobine d'excitation bobinée autour de ladite couronne externe.  a first excitation coil wound around said central stud, and a second excitation coil wound around said outer ring.
Il est également proposé un dispositif pour capter les sons d'un instrument de musique à cordes, qui est apte à être placé sur ledit instrument pour mesurer la vibration d'au moins une corde.  There is also provided a device for capturing the sounds of a string musical instrument, which is adapted to be placed on said instrument for measuring the vibration of at least one string.
Le dispositif peut comprendre :  The device may include:
- un circuit magnétique sensiblement en forme de cylindre définissant une zone de mesure permettant de mesurer la vibration d'une corde de l'instrument sans être notablement affecté par la vibration de cordes voisines ;  a substantially cylindrical magnetic circuit defining a measurement zone for measuring the vibration of a string of the instrument without being significantly affected by the vibration of adjacent strings;
- un circuit magnétique de forme sensiblement allongée, définissant une zone de mesure permettant de mesurer la vibration d'une pluralité de cordes de l'instrument.  a magnetic circuit of substantially elongated shape, defining a measurement zone making it possible to measure the vibration of a plurality of strings of the instrument.
Il est également proposé un dispositif selon l'invention pour capter les vibrations d'un objet d'intérêt de l'une des formes suivantes :  There is also provided a device according to the invention for capturing the vibrations of an object of interest of one of the following forms:
- un élément ou une paroi d'un instrument de musique,  - an element or wall of a musical instrument,
- une membrane sensible à une vibration acoustique.  a membrane sensitive to an acoustic vibration.
Suivant un autre aspect, il est proposé un système de génération de sons comprenant un dispositif de mesure de vibrations selon l'invention, et des moyens électroniques et de calcul pour générer des sons à partir des vibrations mesurées. Le système de génération de sons selon l'invention peut être configuré de telle sorte à pouvoir générer des sons reproduisant les sonorités d'un microphone déterminé et/ou de l'assemblage d'un instrument et d'un microphone déterminés. In another aspect, there is provided a sound generation system comprising a vibration measuring device according to the invention, and electronic and calculation means for generating sounds from the measured vibrations. The sound generation system according to the invention can be configured so as to be able to generate sounds reproducing the sounds of a given microphone and / or the assembly of a certain instrument and microphone.
Ainsi, l'invention permet d'apporter un certain nombre d'innovations, notamment en ce qui concerne son utilisation pour capter les sons d'instruments. Il devient en particulier possible :  Thus, the invention makes it possible to make a number of innovations, particularly as regards its use for capturing instrument sounds. In particular, it becomes possible:
- de capter toutes les informations issues des vibrations des cordes de manière linéaire, et notamment les fréquences extrêmes du spectre audible (infra basses, basses et aiguës) ;  to capture all the information coming from the vibrations of the strings in a linear manner, and in particular the extreme frequencies of the audible spectrum (infra low, low and high);
- de reproduire par un filtrage électronique associé les sonorités de microphones de l'art antérieur dont les réponses fréquentielles sont celles d'un circuit RLC (résistance, inductance, capacité) résonnant dans le spectre audible ;  reproducing, by an associated electronic filtering, the sonorities of microphones of the prior art whose frequency responses are those of an RLC circuit (resistance, inductance, capacitance) resonating in the audible spectrum;
- d'avoir une dynamique plus importante que les systèmes de l'art antérieur, et donc un rapport signal sur bruit plus performant ;  to have a greater dynamic than the systems of the prior art, and therefore a more effective signal-to-noise ratio;
- de faire une transduction à haute fidélité des vibrations des cordes d'instruments ;  - to make a high-fidelity transduction of the vibrations of the strings of instruments;
- d'obtenir davantage de sonorités grâce à la possibilité d'exploiter des informations non captées par les microphones de l'art antérieur.  to obtain more sounds thanks to the possibility of exploiting information not picked up by the microphones of the prior art.
Description des figures et modes de réalisation Description of the Figures and Embodiments
D'autres avantages et particularités de l'invention apparaîtront à la lecture de la description détaillée de mises en œuvre et de modes de réalisation nullement limitatifs, et des dessins annexés suivants : Other advantages and particularities of the invention will appear on reading the detailed description of implementations and non-limiting embodiments, and the following appended drawings:
- la figure 1 illustre un instrument à cordes sous la forme d'une guitare électrique équipée de dispositifs selon l'invention,  FIG. 1 illustrates a stringed instrument in the form of an electric guitar equipped with devices according to the invention,
- la figure 2 illustre une vue de profil de dispositif selon l'invention, FIG. 2 illustrates a device profile view according to the invention,
- la figure 3(a) illustre une première variante de mode de bobinage dans laquelle le dispositif selon l'invention est sensible essentiellement à des déplacements verticaux comme illustré à la figure 3(b), FIG. 3 (a) illustrates a first embodiment of winding mode in which the device according to the invention is substantially sensitive to vertical displacements as illustrated in FIG. 3 (b),
- la figure 4(a) illustre une seconde variante de mode de bobinage dans lequel le dispositif selon l'invention est sensible essentiellement à des déplacements horizontaux comme illustré à la figure 4(b),  FIG. 4 (a) illustrates a second variant of winding mode in which the device according to the invention is substantially sensitive to horizontal displacements as illustrated in FIG. 4 (b),
- la figure 5 illustre un schéma électrique de dispositif selon l'invention, - la figure 6 illustre un mode de réalisation de dispositif selon l'invention adapté à la mesure de déplacement d'une corde, avec à la figure 6(a) le dispositif de la figure 6(b) présenté sans blindage, FIG. 5 illustrates a device electrical diagram according to the invention, FIG. 6 illustrates a device embodiment according to the invention adapted to measuring the movement of a rope, with in FIG. 6 (a) the device of FIG. 6 (b) presented without shielding,
- la figure 7 illustre une vue de dessus de dispositif selon l'invention selon un mode de réalisation adapté à la mesure de déplacement d'une pluralité de cordes simultanément.  - Figure 7 illustrates a top view of the device according to the invention according to an embodiment adapted to the measurement of displacement of a plurality of ropes simultaneously.
En référence à la figure 1, on va décrire des modes de réalisation, nullement limitatifs, de dispositifs de collecte de son selon l'invention pour mesurer la vibration des cordes d'un instrument de musique tel qu'une guitare.  With reference to FIG. 1, non-limiting embodiments of sound collection devices according to the invention will be described for measuring the vibration of the strings of a musical instrument such as a guitar.
Le dispositif selon l'invention ou capteur 2 est conçu de telle sorte à pouvoir être fixé sur le corps d'une guitare 1, sous les cordes 4. Il peut en particulier être réalisé de telle sorte à pouvoir être fixé sur des instruments 1 existants, dans des emplacements prévus pour des capteurs de son de l'art antérieur.  The device according to the invention or sensor 2 is designed so as to be fixed on the body of a guitar 1, under the ropes 4. It can in particular be made so that it can be fixed on existing instruments 1 in locations provided for sound sensors of the prior art.
De manière classique, l'instrument 1 comprend un connecteur 3 qui permet de relier le ou les capteurs 2 à une électronique et/ou un système de sonorisation externe.  In a conventional manner, the instrument 1 comprises a connector 3 which makes it possible to connect the sensor or sensors 2 to an electronics and / or an external sound system.
En référence à la figure 2, le capteur 2 comprend un circuit magnétique essentiellement constitué d'un élément 10 en matériau magnétique ou ferromagnétique tel que de la ferrite. Cet élément 10 a un profil sensiblement en forme de « U » ou de « H », avec une base 16 et des branches 15 sensiblement parallèles qui s'élèvent de manière sensiblement perpendiculaire à cette base.  With reference to FIG. 2, the sensor 2 comprises a magnetic circuit consisting essentially of an element 10 made of magnetic or ferromagnetic material such as ferrite. This element 10 has a substantially U-shaped or "H" shaped profile, with a base 16 and substantially parallel branches 15 which rise substantially perpendicularly to this base.
Le dispositif comprend en outre des bobines d'inductance 11, 12, 13 réalisées avec un élément conducteur à l'électricité tel que du fil de cuivre bobiné autour de l'élément ferromagnétique 10, directement ou sur un support. Ces bobines sont reliées entre elles et/ou à une électronique de contrôle par des fils de liaison 14. Elles comprennent une bobine de mesure 13 bobinée autour de la base 16, et deux bobines d'excitation 11, et 12 bobinées respectivement autour des branches 15 et de la base 16 du circuit magnétique.  The device further comprises inductance coils 11, 12, 13 made with an electrically conductive element such as copper wire wound around the ferromagnetic element 10, directly or on a support. These coils are connected together and / or to a control electronics by connecting wires 14. They comprise a measuring coil 13 wound around the base 16, and two excitation coils 11 and 12 respectively wound around the branches 15 and the base 16 of the magnetic circuit.
Les bobines d'excitation 11, 12 et de mesure 13 sont couplées de manière électromagnétique par le circuit magnétique et en particulier par l'élément ferromagnétique 10. Lorsque les bobines d'excitation 11, 12 sont excitées par un signal alternatif, elles génèrent des flux magnétiques dont une partie au moins traverse la bobine de mesure, et génère une tension induite à ses bornes. The excitation coils 11, 12 and measuring coils 13 are electromagnetically coupled by the magnetic circuit and in particular by the ferromagnetic element 10. When the excitation coils 11, 12 are excited by an alternating signal, they generate magnetic fluxes of which at least part passes through the measuring coil, and generates a voltage induced at its terminals.
La structure du circuit magnétique et des bobinages est conçue de telle sorte à définir une zone de mesure 17 qui s'étend sensiblement au-delà des branches 15 du circuit magnétique. Un objet conducteur à l'électricité (telle qu'une corde d'instrument 4) présent dans cette zone de mesure 17 perturbe les flux magnétiques traversant la bobine de mesure 13, ce qui permet de le détecter.  The structure of the magnetic circuit and the coils is designed so as to define a measurement zone 17 which extends substantially beyond the branches 15 of the magnetic circuit. An electrically conductive object (such as an instrument string 4) present in this measurement zone 17 disrupts the magnetic flux passing through the measuring coil 13, which makes it possible to detect it.
Cette zone de mesure 17 constitue un entrefer du circuit magnétique, ce qui permet de la confiner spatialement. En effet, les lignes de champ magnétique présentes dans le circuit magnétique sont peu influencées par des objets à proximité de l'élément ferromagnétique 10, à l'exception de la zone de mesure 17. Cet effet de confinement est important pour limiter les perturbations de l'environnement, faciliter l'intégration du capteur 2 sur un instrument 1, et limiter les effets de diaphonie entre cordes 4 voisines.  This measurement zone 17 constitutes an air gap of the magnetic circuit, which makes it possible to confine it spatially. Indeed, the magnetic field lines present in the magnetic circuit are little influenced by objects in the vicinity of the ferromagnetic element 10, with the exception of the measurement zone 17. This confinement effect is important to limit the disturbances of the environment, facilitate the integration of the sensor 2 on an instrument 1, and limit the effects of crosstalk between neighboring ropes 4.
Il est à noter que le fait de mettre en œuvre un circuit magnétique avec (au moins) deux branches 15 améliore sensiblement le confinement de la zone de mesure 17 par rapport aux dispositifs de l'art antérieur dans lesquels le circuit magnétique est en général constitué d'un plot unique à proximité de la corde 4.  It should be noted that the fact of implementing a magnetic circuit with (at least) two branches 15 substantially improves the confinement of the measurement zone 17 with respect to the devices of the prior art in which the magnetic circuit is generally constituted a single stud near the rope 4.
Les figures 3 et 4 présentent deux variantes de modes de réalisation des bobinages qui permettent de réaliser des capteurs 2 essentiellement sensibles, respectivement, à des modes de vibration des cordes 4 verticaux (c'est-à-dire sensiblement parallèles aux branches 15) ou horizontaux (c'est- à-dire sensiblement parallèles à la base 16).  FIGS. 3 and 4 show two variants of embodiments of the windings which make it possible to produce sensors 2 that are essentially sensitive, respectively, to modes of vibration of the vertical ropes 4 (that is to say substantially parallel to the branches 15) or horizontal (that is to say substantially parallel to the base 16).
C'est un avantage de l'invention de pouvoir mesurer de manière distincte des modes de vibrations horizontaux et verticaux des cordes 4. Cela permet de fournir une information plus riche et/ou mieux définie à des systèmes de génération de sons. On peut soit privilégier la mesure de l'un ou l'autre mode en montant un capteur 2 adéquat sur un instrument 1, soit mesurer simultanément les deux modes, par exemple en montant deux capteurs 2 sur l'instrument 1.  It is an advantage of the invention to be able to separately measure horizontal and vertical vibration modes of the strings 4. This makes it possible to provide richer and / or better defined information to sound generation systems. One can either favor the measurement of one or the other mode by mounting a suitable sensor 2 on an instrument 1, or simultaneously measure the two modes, for example by mounting two sensors 2 on the instrument 1.
Dans la variante présentée à la figure 3a, le capteur 1 comprend : - une bobine de mesure 13 R placée autour de la base 16 du circuit magnétique 10, In the variant shown in FIG. 3a, the sensor 1 comprises: a measuring coil 13 R placed around the base 16 of the magnetic circuit 10,
- une bobine d'excitation 12 E2 placée autour de la base 16 du circuit magnétique 10, et  an excitation coil 12 E2 placed around the base 16 of the magnetic circuit 10, and
- une bobine d'excitation 11 El, constituée de deux bobines partielles l ia, 11b respectivement placées autour des branches 15 du circuit magnétique 10.  an excitation coil 11 El consisting of two partial coils 11a, 11b respectively placed around the branches 15 of the magnetic circuit 10.
Les bobines d'excitation l ia, 11b et 12 sont reliées en série et connectées à une source d'excitation Ve alternative.  The excitation coils 11a, 11b and 12 are connected in series and connected to an alternating excitation source Ve.
La bobine d'excitation 12 est fortement couplée à la bobine de mesure The excitation coil 12 is strongly coupled to the measuring coil
13 dans le sens où l'essentiel du flux magnétique 31 qu'elle génère traverse également la bobine de mesure 13. En outre, le flux 31 généré par la bobine d'excitation 12 et couplé dans la bobine de mesure 13 est pas ou peu affecté par la présence d'un objet 4 dans la zone de mesure 17. 13 in the sense that most of the magnetic flux 31 that it generates also passes through the measuring coil 13. In addition, the flux 31 generated by the excitation coil 12 and coupled in the measuring coil 13 is not or little affected by the presence of an object 4 in the measuring zone 17.
Les deux bobines partielles l ia et 11b sont bobinées en sens opposé, de telle sorte à générer respectivement un flux 30 sortant dans la zone de mesure 17 (par exemple au niveau de la bobine 11b) et un flux 30 entrant dans la branche 15 (par exemple au niveau de la bobine l ia) .  The two partial coils 11a and 11b are wound in opposite directions, so as to respectively generate a flux 30 exiting in the measuring zone 17 (for example at the level of the coil 11b) and a stream 30 entering the branch 15 ( for example at the level of the coil l ia).
Ces bobines l ia, 11b étant placées de part et d'autre de la zone de mesure 17, elles génèrent un flux 30 qui est fortement affecté par la présence d'un objet 4 dans la zone de mesure 17.  These coils 11a, 11b being placed on either side of the measuring zone 17, they generate a flux 30 which is strongly affected by the presence of an object 4 in the measurement zone 17.
Les bobines d'excitation l ia, 11b et 12 sont bobinées de telle sorte que leurs flux respectifs 30, 31 au travers de la bobine de mesure 13 soient en opposition de phase. En outre, leurs inductances sont ajustées de telle sorte que, en tenant compte du couplage, le flux résultant dans la bobine de mesure 13 soit presque nul, c'est-à-dire que les flux 30, 31 se compensent au moins partiellement au niveau de la bobine de mesure 13.  The excitation coils 11a, 11b and 12 are wound so that their respective flows 30, 31 through the measuring coil 13 are in phase opposition. In addition, their inductances are adjusted so that, taking into account the coupling, the resulting flux in the measuring coil 13 is almost zero, that is to say that the fluxes 30, 31 compensate for themselves at least partially at level of the measuring coil 13.
Dans la mesure où la bobine d'excitation l ia, 11b est moins bien couplée à la bobine de mesure 13 que la bobine d'excitation 12 (ou présente des flux de fuite plus importants), elle comprend un nombre total de spires supérieur.  Since the excitation coil 11a, 11b is less well coupled to the measuring coil 13 than the excitation coil 12 (or has larger leakage fluxes), it comprises a greater total number of turns.
Comme illustré à la figure 3b, ce montage permet de mesurer le mouvement 32 d'un objet 4 selon l'axe vertical Oz (sensiblement parallèle aux branches 15) indépendamment des variations de position de ce même objet 4 dans le plan sur les axes perpendiculaires Ox et Oy. En effet, les champs magnétiques générés par les bobines d'excitation 11 et 12 sont en opposition de phase et se compensent au moins partiellement au travers de la bobine de mesure 13 en l'absence d'objet 4. En outre, seul le champ de la bobine 11 est notablement modifié par la présence de l'objet 4. As illustrated in FIG. 3b, this arrangement makes it possible to measure the movement 32 of an object 4 along the vertical axis Oz (substantially parallel to the branches 15) independently of the variations of position of this same object 4 in the plane on the perpendicular axes Ox and Oy. Indeed, the magnetic fields generated by the excitation coils 11 and 12 are in phase opposition and compensate at least partially through the measuring coil 13 in the absence of object 4. In addition, only the field of the coil 11 is significantly modified by the presence of the object 4.
Les champs magnétiques générés par les bobines d'excitation partielle lia, 11b de la bobine 11 se compensent mutuellement lorsque l'objet 4 décrit un mouvement selon l'axe Ox et ne donnent donc pas lieu à une variation de la tension mesurée Vs dans la bobine de mesure 13.  The magnetic fields generated by the partial excitation coils 11a, 11b of the coil 11 compensate each other when the object 4 describes a movement along the axis Ox and therefore do not give rise to a variation of the measured voltage Vs in the measuring coil 13.
En outre, dans la mesure où la cible 4 telle qu'une corde d'instrument est d'une dimension considérée comme infinie selon l'axe Oy par rapport aux dimensions du capteur 1, aucune mesure n'est effectuée sur cet axe.  In addition, insofar as the target 4 such that an instrument string is of a dimension considered as infinite along the axis Oy with respect to the dimensions of the sensor 1, no measurement is made on this axis.
Dans la variante présentée à la figure 4a, le capteur 1 comprend :  In the variant shown in FIG. 4a, the sensor 1 comprises:
- une bobine de mesure 13 R placée autour de la base 16 du circuit magnétique 10,  a measuring coil 13 R placed around the base 16 of the magnetic circuit 10,
- une bobine d'excitation 42 El placée autour d'une branche 15 du circuit magnétique 10, et  an excitation coil 42 El placed around a branch 15 of the magnetic circuit 10, and
- une bobine d'excitation 43 E2 placée autour de l'autre branche 15 du circuit magnétique 10.  an excitation coil 43 E2 placed around the other branch 15 of the magnetic circuit 10.
Les bobines d'excitation 42 et 43 sont reliées en série et connectées à une source d'excitation Ve alternative. La fréquence d'excitation peut être de l'ordre de 1 MHz.  The excitation coils 42 and 43 are connected in series and connected to an alternative excitation source Ve. The excitation frequency may be of the order of 1 MHz.
Les deux bobines d'excitation 42, 43 sont couplées de manière sensiblement identique avec la bobine de mesure 13.  The two excitation coils 42, 43 are coupled substantially identically to the measuring coil 13.
Les deux bobines d'excitation 42, 43 sont bobinées en sens opposé, de telle sorte à générer dans la zone de mesure 17 des flux 40, 41 d'orientation opposée.  The two excitation coils 42, 43 are wound in opposite directions, so as to generate in the measurement zone 17 flows 40, 41 of opposite orientation.
Ces bobines d'excitation 42, 43 étant placées de part et d'autre de la zone de mesure 17, les flux 40, 41 qu'elles génèrent sont fortement affectés par la présence d'un objet 4 dans la zone de mesure 17.  These excitation coils 42, 43 being placed on either side of the measurement zone 17, the fluxes 40, 41 that they generate are strongly affected by the presence of an object 4 in the measurement zone 17.
Les bobines d'excitation 42, 43 sont bobinées de telle sorte que leurs flux respectifs 40, 41 au travers de la bobine de mesure 13 soient également en opposition de phase, et que le flux résultant dans la bobine de mesure 13 soit proche de zéro, c'est-à-dire que les flux 40, 41 se compensent au moins partiellement au niveau de la bobine de mesure 13. Comme illustré à la figure 4b, ce montage permet de mesurer le mouvement 44 d'un objet 4 selon l'axe horizontal Ox (sensiblement parallèle à la base 16) indépendamment des variations de position de ce même objet 4 selon les axes perpendiculaires Oz et Oy. The excitation coils 42, 43 are wound so that their respective fluxes 40, 41 through the measuring coil 13 are also in phase opposition, and that the resulting flux in the measuring coil 13 is close to zero. i.e., the fluxes 40, 41 compensate each other at least partially at the level of the measuring coil 13. As illustrated in FIG. 4b, this arrangement makes it possible to measure the movement 44 of an object 4 along the horizontal axis Ox (substantially parallel to the base 16) independently of the variations of position of this same object 4 along the perpendicular axes Oz and Oy.
En effet, les champs magnétiques générés par les bobines d'excitation Indeed, the magnetic fields generated by the excitation coils
42 et 43 sont en opposition de phase et se compensent au moins partiellement au travers de la bobine de mesure 13 en l'absence d'objet 4. En outre, les champs magnétiques générés respectivement par la bobine d'excitation 42 et par la bobine d'excitation 43 sont tous deux modifiés par la présence de l'objet 4. 42 and 43 are in phase opposition and compensate at least partially through the measuring coil 13 in the absence of object 4. In addition, the magnetic fields generated respectively by the excitation coil 42 and the coil excitation 43 are both modified by the presence of the object 4.
Les champs magnétiques générés par les bobines d'excitation 42 et 43 se compensent mutuellement lorsque l'objet d'intérêt 4 décrit un mouvement selon l'axe vertical Oz et ne donnent pas lieu à une variation de la tension Vs dans la bobine de mesure 13.  The magnetic fields generated by the excitation coils 42 and 43 compensate each other when the object of interest 4 describes a movement along the vertical axis Oz and does not give rise to a variation of the voltage Vs in the measuring coil 13.
II est nécessaire que l'objet 4 soit sensiblement centré par rapport aux deux bobines d'excitation 42, 43 et que son mouvement 44 soit plus petit que la distance séparant le centre des bobines d'excitation 42 et 43. En effet, la réjection du mouvement de l'objet 4 selon l'axe Oz est d'autant plus grande lorsque l'objet 4 est centré entre les bobines d'excitation 42 et 43.  It is necessary that the object 4 is substantially centered with respect to the two excitation coils 42, 43 and that its movement 44 is smaller than the distance separating the center of the excitation coils 42 and 43. Indeed, the rejection the movement of the object 4 along the axis Oz is even greater when the object 4 is centered between the excitation coils 42 and 43.
En outre, dans la mesure où la cible 4, telle qu'une corde d'instrument, est d'une dimension considérée comme infinie selon l'axe Oy par rapport aux dimensions du capteur 1, aucune mesure n'est effectuée sur cet axe.  In addition, since the target 4, such as an instrument chord, is of a dimension considered as infinite along the axis Oy with respect to the dimensions of the sensor 1, no measurement is made on this axis. .
La figure 5 présente une chaîne d'acquisition et de traitement des signaux de mesure.  Figure 5 shows a chain of acquisition and processing of measurement signals.
Elle comprend une partie d'excitation, qui comprend un oscillateur 52 et un amplificateur 53, pour générer un signal d'excitation Ve à hautes fréquences, de l'ordre de 1 MHz.  It comprises an excitation part, which comprises an oscillator 52 and an amplifier 53, for generating a high frequency excitation signal Ve, of the order of 1 MHz.
L'amplificateur 53 alimente des bobines d'excitation 50, 51 connectées en série et agencées notamment selon les modes de réalisations des figures 3 et 4.  The amplifier 53 supplies excitation coils 50, 51 connected in series and arranged in particular according to the embodiments of FIGS. 3 and 4.
La chaîne de traitement comprend un amplificateur 54, un redresseur 55 et un filtre passe-bas 56. Elle permet de redresser et filtrer la tension induite Vr mesurée aux bornes de la bobine de mesure 13 pour en extraire l'enveloppe, représentative de la vibration de l'objet 4. Le signal démodulé peut ensuite être traité par des systèmes de sonorisation, de génération ou de synthèse de sons, numériques ou analogiques. The processing chain comprises an amplifier 54, a rectifier 55 and a low-pass filter 56. It makes it possible to straighten and filter the induced voltage Vr measured across the measuring coil 13 to extract the envelope, representative of the vibration of the object 4. The demodulated signal can then be processed by sound systems, digital or analog sound generation or synthesis.
Le nombre de spires de la bobine de mesure 13 est maximisé pour obtenir une tension Vs maximale et une bande passante couvrant au moins le spectre audible (jusqu'à 20kHz).  The number of turns of the measuring coil 13 is maximized to obtain a maximum voltage Vs and a bandwidth covering at least the audible spectrum (up to 20 kHz).
Il a été démontré, notamment dans le mode de réalisation de la figure 3, que le capteur est plus sensible lorsque la tension Vs en l'absence d'objet 4 n'est pas égale à zéro mais plutôt à une valeur faible qui correspond au cas où la contribution de E2 dans R et plus grande que celle de El dans R.  It has been demonstrated, particularly in the embodiment of FIG. 3, that the sensor is more sensitive when the voltage Vs in the absence of object 4 is not equal to zero but rather to a low value corresponding to the case where the contribution of E2 in R and greater than that of El in R.
Il est ainsi possible d'obtenir un signal électrique représentatif des mouvements d'un objet 4 tel qu'une corde d'instrument de musique :  It is thus possible to obtain an electrical signal representative of the movements of an object 4 such as a musical instrument string:
- suivant une ou des directions déterminées,  - in one or more directions,
- de manière linéaire, et  - linearly, and
- sur toute une bande de fréquence allant du continu à plusieurs dizaines de kHz.  - over a whole frequency band from DC to several tens of kHz.
En référence à la figure 6, le capteur 2 peut être réalisé sous une forme sensiblement cylindrique, avec un diamètre de l'ordre de 5 mm. La configuration des bobines d'excitation 11, 12 peut être selon le mode de réalisation de la figure 3 ou celui de la figure 4. Le capteur 1 est en outre pourvu d'un blindage 60 sur son pourtour qui améliore son immunité aux perturbations, et le confinement de la zone de mesure 17.  With reference to FIG. 6, the sensor 2 can be made in a substantially cylindrical shape with a diameter of the order of 5 mm. The configuration of the excitation coils 11, 12 may be according to the embodiment of FIG. 3 or that of FIG. 4. The sensor 1 is further provided with a shield 60 on its periphery which improves its immunity to disturbances, and the confinement of the measurement zone 17.
Ce mode de réalisation permet d'équiper un instrument 1 avec des capteurs 2 de telle sorte que chaque capteur 2 ne mesure que la vibration d'une corde 4 individuelle.  This embodiment makes it possible to equip an instrument 1 with sensors 2 so that each sensor 2 only measures the vibration of an individual rope 4.
En référence à la figure 7, le capteur 2 peut être réalisé sous une forme sensiblement allongée, de telle sorte à présenter une zone de mesure 17 apte à englober plusieurs cordes 4 (ou toutes les cordes 4) d'un instrument 1.  With reference to FIG. 7, the sensor 2 can be made in a substantially elongated form, so as to have a measurement zone 17 capable of including several ropes 4 (or all the ropes 4) of an instrument 1.
La figure 7 présente une vue de dessus d'un capteur 2 avec une base 16 et deux branches 15, dont une vue de profil correspond à le figure 2.  FIG. 7 shows a view from above of a sensor 2 with a base 16 and two branches 15, a profile view of which corresponds to FIG. 2.
La configuration des bobines d'excitation 11, 12 est celle du mode de réalisation de la figure 3.  The configuration of the excitation coils 11, 12 is that of the embodiment of FIG.
Ainsi le capteur 2 est sensible au déplacement vertical 32 selon l'axe Oz des cordes 4, y compris lorsque les cordes s'étendent dans la direction des branches 15 selon l'axe Oy. Ce mode de réalisation permet d'équiper un instrument 1 avec un capteur unique, simple, qui fournit un signal Vs représentatif de l'ensemble des vibrations des cordes 4 qui traversent la zone de mesure 17. Thus the sensor 2 is sensitive to the vertical movement 32 along the axis Oz of the ropes 4, including when the ropes extend in the direction of the branches 15 along the axis Oy. This embodiment makes it possible to equip an instrument 1 with a single, simple sensor, which provides a signal Vs representative of all the vibrations of the ropes 4 which pass through the measurement zone 17.
Suivant des variantes,  According to variants,
- Les bobines d'excitation peuvent être reliées à l'électronique de toutes les façons possibles, notamment en série, en parallèle, ou alimentées par des sources d'excitations différentes ;  - Excitation coils can be connected to the electronics in all possible ways, especially in series, in parallel, or powered by different excitation sources;
- La démodulation du signal représentatif de la vibration peut être effectuée par des moyens numériques, après une acquisition directe du signal Vr. Elle peut également être effectuée par un démodulateur synchrone.  The demodulation of the signal representative of the vibration can be carried out by digital means, after a direct acquisition of the signal Vr. It can also be performed by a synchronous demodulator.
Bien sûr, l'invention n'est pas limitée aux exemples qui viennent d'être décrits et de nombreux aménagements peuvent être apportés à ces exemples sans sortir du cadre de l'invention.  Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

Claims

REVENDICATIONS
1. Dispositif capteur (2) pour mesurer un déplacement et/ou une vibration (32, 44) d'au moins un objet d'intérêt (4), notamment pour instruments de musique, qui comprend : Sensor device (2) for measuring a displacement and / or a vibration (32, 44) of at least one object of interest (4), in particular for musical instruments, which comprises:
- au moins deux bobines d'inductance d'excitation (11, lia, 11b, 42, 43, 50, 51) électriquement reliées à au moins une source électrique d'excitation (52), et aptes à générer des flux magnétiques d'excitation (30, 31, 40, 41), et - au moins une bobine d'inductance de mesure (13), électriquement reliée à des moyens électriques de mesure (54, 55, 56) aptes à mesurer des signaux électriques induits (Vs),  at least two excitation inductance coils (11, 11a, 11b, 42, 43, 50, 51) electrically connected to at least one electrical excitation source (52), and capable of generating magnetic fluxes excitation (30, 31, 40, 41), and - at least one measuring inductance coil (13), electrically connected to electrical measuring means (54, 55, 56) capable of measuring induced electrical signals (Vs )
caractérisé en ce qu'il comprend en outre :  characterized in that it further comprises:
- un circuit magnétique (10) reliant magnétiquement les bobines d'excitation (11, lia, 11b, 42, 43, 50, 51) et de mesure (13), et comprenant une zone de mesure (17) dans laquelle la présence d'objets d'intérêt (4) affecte des flux magnétiques (30, 31, 40, 41) issus de bobines d'excitation (11, lia, 11b, 42, 43, 50, 51) et traversant ladite ou lesdites bobine(s) de mesure (13), et  a magnetic circuit (10) magnetically connecting the excitation coils (11, 11a, 11b, 42, 43, 50, 51) and measuring coils (13), and comprising a measurement zone (17) in which the presence of of interest (4) affects magnetic fluxes (30, 31, 40, 41) from excitation coils (11, 11a, 11b, 42, 43, 50, 51) and passing through said coil (s) ) measuring (13), and
- des bobines d'excitation (11, lia, 11b, 42, 43, 50, 51) disposées de telle sorte à générer, en l'absence d'objet d'intérêt (4) dans la zone de mesure (17), des flux magnétiques (30, 31, 40, 41) qui se compensent sensiblement dans l'au moins une bobine de mesure (13).  excitation coils (11, 11a, 11b, 42, 43, 50, 51) arranged so as to generate, in the absence of object of interest (4) in the measurement zone (17), magnetic fluxes (30, 31, 40, 41) which substantially compensate in the at least one measuring coil (13).
2. Le dispositif de la revendication 1, qui comprend une bobine de mesure (13), une première bobine d'excitation (12) fortement couplée à ladite bobine de mesure (13) de telle sorte que le flux (31) généré par ladite première bobine d'excitation (12) dans la bobine de mesure (13) soit peu affecté par la présence d'un objet (4) dans la zone de mesure (17), et une seconde bobine d'excitation (11, lia, 11b) plus faiblement couplée à ladite bobine de mesure (13) de telle sorte que le flux (30) généré par ladite seconde bobine d'excitation (11, lia, 11b) dans la bobine de mesure (13) soit fortement affecté par la présence d'un objet (4) dans la zone de mesure (17). 2. The device of claim 1, which comprises a measuring coil (13), a first excitation coil (12) strongly coupled to said measuring coil (13) so that the flux (31) generated by said first excitation coil (12) in the measuring coil (13) is not affected by the presence of an object (4) in the measurement zone (17), and a second excitation coil (11, 11a, 11b) more weakly coupled to said measuring coil (13) so that the flux (30) generated by said second excitation coil (11, 11a, 11b) in the measuring coil (13) is strongly affected by the presence of an object (4) in the measuring zone (17).
3. Le dispositif de la revendication 1, qui comprend une bobine de mesure (13) et deux bobines d'excitation (42, 43) couplées à ladite bobine de mesure (13) de telle sorte que le flux (40, 41) généré par lesdites bobines d'excitation (42, 43) dans la bobine de mesure (13) soit affecté de manière sensiblement identique par la présence d'un objet (4) dans la zone de mesure (17). The device of claim 1, which comprises a measuring coil (13) and two excitation coils (42, 43) coupled to said measuring coil (13) so that the flux (40, 41) generated by said excitation coils (42, 43) in the measuring coil (13) is substantially identically affected by the presence of an object (4) in the measuring area (17).
4. Le dispositif selon l'une des revendications précédentes, qui comprend des bobines d'excitation (11, lia, 11b, 42, 43, 50, 51) et de mesure (13) réalisées, chacune, selon l'une des formes suivantes : un bobinage unique, une pluralité de bobinages partiels répartis sur le circuit magnétique. 4. The device according to one of the preceding claims, which comprises excitation coils (11, 11a, 11b, 42, 43, 50, 51) and measuring coils (13) each made in one of the forms following: a single winding, a plurality of partial windings distributed on the magnetic circuit.
5. Le dispositif de l'une des revendications précédentes, dans lequel le circuit magnétique (10) comprend une partie constituée au moins partiellement de matériau magnétique, de section sensiblement en forme de « U » avec une base (16) et deux branches (15) sensiblement parallèles, la zone de mesure (17) s'étendant sensiblement au delà et entre les extrémités desdites branches (15) à l'opposé de ladite base (16). 5. The device according to one of the preceding claims, in which the magnetic circuit (10) comprises a part made at least partially of magnetic material, of substantially U-shaped section with a base (16) and two branches ( 15) substantially parallel, the measuring zone (17) extending substantially beyond and between the ends of said branches (15) opposite said base (16).
6. Le dispositif de la revendication 5, qui comprend une bobine de mesure (13) bobinée autour de la base (16), une première bobine d'excitation (12) bobinée autour de ladite base (16), et une seconde bobine d'excitation (11) avec deux bobinages partiels (lia, 11b) bobinés respectivement autour des deux branches (15) de telle sorte à générer dans la zone de mesure (17) respectivement un flux (30) sortant d'une branche (15) et un flux (30) entrant dans l'autre branche (15). 6. The device of claim 5, which comprises a measuring coil (13) wound around the base (16), a first excitation coil (12) wound around said base (16), and a second coil of excitation (11) with two partial windings (11a, 11b) wound respectively around the two branches (15) so as to generate in the measurement zone (17) respectively a flux (30) emerging from a branch (15) and a stream (30) entering the other branch (15).
7. Le dispositif de la revendication 5, qui comprend une bobine de mesure bobinée autour de la base, et deux bobines d'excitation bobinées respectivement autour des deux branches de telle sorte à générer dans la zone de mesure des flux sortant desdites branches. 7. The device of claim 5, which comprises a measuring coil wound around the base, and two excitation coils respectively wound around the two branches so as to generate in the measurement zone flows out of said branches.
8. Le dispositif de la revendication 5, qui comprend une bobine de mesure (13) bobinée autour d'une branche (15), et deux bobines d'excitation (50, 51) bobinées respectivement autour des deux branches (15) de telle sorte à générer dans la zone de mesure (17) des flux sortant desdites branches (15). 8. The device of claim 5, which comprises a measuring coil (13) wound around a branch (15), and two excitation coils (50, 51) respectively wound around the two branches (15) of such so as to generate in the measurement zone (17) flows leaving said branches (15).
9. Le dispositif de l'une des revendications 1 à 4, dans lequel le circuit magnétique (10) comprend : The device of one of claims 1 to 4, wherein the magnetic circuit (10) comprises:
- une partie constituée au moins partiellement de matériau magnétique, de section sensiblement en forme de « E » avec une base (16), une branche centrale et deux branches latérales (15) sensiblement parallèles, la zone de mesure (17) s'étendant sensiblement au delà et entre les extrémités desdites branches (15) à l'opposé de ladite base (16),  a part made at least partially of magnetic material, of substantially E-shaped section with a base (16), a central branch and two substantially parallel lateral branches (15), the measuring zone (17) extending substantially beyond and between the ends of said legs (15) opposite said base (16),
- une bobine de mesure (13) bobinée autour de ladite branche centrale, a measuring coil (13) wound around said central branch,
- une première bobine d'excitation bobinée (50) autour de ladite branche centrale, et a first wound excitation coil (50) around said central branch, and
- une seconde bobine d'excitation (51) avec deux bobinages partiels bobinés respectivement autour des deux branches latérales (15).  - A second excitation coil (51) with two partial windings respectively wound around the two lateral branches (15).
10. Le dispositif de l'une des revendications 1 à 4, dans lequel le circuit magnétique comprend : The device of one of claims 1 to 4, wherein the magnetic circuit comprises:
- une partie constituée au moins partiellement de matériau magnétique, de forme sensiblement cylindrique et de section diamétrale sensiblement en forme de « E » avec une base, un plot central et une couronne externe, la zone de mesure s'étendant sensiblement à l'opposé de ladite base,  a part made at least partially of magnetic material, of substantially cylindrical shape and of substantially "E" -shaped diametrical section with a base, a central stud and an outer ring, the measurement zone extending substantially the opposite of said base,
- une bobine de mesure bobinée autour dudit plot central,  a measuring coil wound around said central stud,
- une première bobine d'excitation bobinée autour dudit plot central, et - une seconde bobine d'excitation bobinée autour de ladite couronne externe.  a first excitation coil wound around said central stud, and a second excitation coil wound around said outer ring.
11. Un dispositif (2) selon l'une quelconque des revendications 5 à 9 pour capter les sons d'un instrument de musique (1) à cordes, qui est apte à être placé sur ledit instrument (1) pour mesurer la vibration d'au moins une corde (4). 11. A device (2) according to any one of claims 5 to 9 for capturing the sounds of a musical instrument (1) string, which is adapted to be placed on said instrument (1) to measure the vibration of at least one rope (4).
12. Le dispositif selon la revendication 11, qui comprend un circuit magnétique (10) sensiblement en forme de cylindre définissant une zone de mesure (17) permettant de mesurer la vibration d'une corde (4) de l'instrument ( 1) sans être notablement affecté par la vibration de cordes (4) voisines. The device according to claim 11, which comprises a substantially cylindrical magnetic circuit (10) defining a measurement zone (17) for measuring the vibration of a cord (4) of the instrument (1) without being significantly affected by the vibration of adjacent ropes (4).
13. Le dispositif selon la revendication 11, qui comprend un circuit magnétique ( 10) de forme sensiblement allongée, définissant une zone de mesure ( 17) permettant de mesurer la vibration d'une pluralité de cordes (4) de l'instrument ( 1) . The device according to claim 11, which comprises a substantially elongated magnetic circuit (10) defining a measurement zone (17) for measuring the vibration of a plurality of strings (4) of the instrument (1). ).
14. Un dispositif selon l'une quelconque des revendications 1 à 10 pour capter les vibrations d'un objet d'intérêt de l'une des formes suivantes : 14. A device according to any one of claims 1 to 10 for sensing the vibrations of an object of interest of one of the following forms:
- un élément ou une paroi d'un instrument de musique,  - an element or wall of a musical instrument,
- une membrane sensible à une vibration acoustique.  a membrane sensitive to an acoustic vibration.
15. Un système de génération de sons comprenant un dispositif de mesure de vibrations (2) selon l'une quelconque des revendications précédentes, et des moyens électroniques et de calcul pour générer des sons à partir des vibrations mesurées. 15. A sound generation system comprising a vibration measuring device (2) according to any one of the preceding claims, and electronic and computing means for generating sounds from the measured vibrations.
16. Le système de génération de sons de la revendication 15, configuré de telle sorte à pouvoir générer des sons reproduisant les sonorités d'un microphone déterminé et/ou de l'assemblage d'un instrument et d'un microphone déterminés. 16. The sound generation system of claim 15, configured so as to be able to generate sounds reproducing the sounds of a particular microphone and / or assembly of a particular instrument and microphone.
EP12801619.3A 2011-12-02 2012-11-09 Vibration sensor device for musical instruments Withdrawn EP2786372A1 (en)

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FR1161074A FR2983621B1 (en) 2011-12-02 2011-12-02 VIBRATION SENSOR DEVICE FOR MUSICAL INSTRUMENTS
PCT/FR2012/052588 WO2013079844A1 (en) 2011-12-02 2012-11-09 Vibration sensor device for musical instruments

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Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015124123A1 (en) * 2014-02-18 2015-08-27 Balluff Gmbh Position measuring apparatus and method for operating the position measuring apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0527654A2 (en) * 1991-08-14 1993-02-17 Fernandes Co., Ltd. An electric stringed instrument having a device for sustaining the vibration of the string

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3226639A (en) * 1961-04-10 1965-12-28 Leeds & Northrup Co Null-flux transducer for use in electrical measuring and control systems
US4143575A (en) * 1976-10-01 1979-03-13 Oliver Richard C Electronic sound generating system for a stringed musical instrument
US4348930A (en) * 1980-01-25 1982-09-14 Chobanian Dennis A Transducer for sensing string vibrational movement in two mutually perpendicular planes
US4378722A (en) * 1981-10-09 1983-04-05 Isakson David A Magnetic pickup for stringed musical instruments
US4501185A (en) * 1983-07-29 1985-02-26 Dimarzio Musical Instrument Pickups Transducer for stringer musical instrument
US5148733A (en) * 1990-03-05 1992-09-22 Seymour Duncan Corporation Pole piece for an electric string instrument to decrease magnetic flux intensity around strings
US5523526A (en) * 1993-07-23 1996-06-04 Genesis Magnetics Corporation Sustaining devices for stringed musical instruments
US6208135B1 (en) * 1994-07-22 2001-03-27 Steve J. Shattil Inductive noise cancellation circuit for electromagnetic pickups
US5789691A (en) 1995-01-17 1998-08-04 Stich; Willi L. Multi-functional coil system for stringed instruments
US5610357A (en) * 1995-10-06 1997-03-11 Frank-Braun; Michael Stringed musical instrument pickup with two electromagnetic coil assemblies having toothed cores
US5767431A (en) * 1995-12-28 1998-06-16 Actodyne General, Inc. Sensor assembly for stringed musical instruments
US6075198A (en) * 1997-08-19 2000-06-13 Grant; W. Gerry Solid body instrument transducer
US6392137B1 (en) * 2000-04-27 2002-05-21 Gibson Guitar Corp. Polyphonic guitar pickup for sensing string vibrations in two mutually perpendicular planes
GB0201465D0 (en) * 2002-01-23 2002-03-13 Roke Manor Research Pre-mri metal detector
US20060021495A1 (en) * 2004-08-02 2006-02-02 Freitas Paul J Electric percussion instruments
US20080245217A1 (en) * 2007-04-07 2008-10-09 Bret Thomas Stewart Nearly Closed Magnetic Flux Electromagnetic Transducer for Instrument Pickups
US7595444B2 (en) * 2007-04-07 2009-09-29 Bret Thomas Stewart Electromagnetic transducer for instrument pickups
US7989690B1 (en) 2007-04-16 2011-08-02 Andrew Scott Lawing Musical instrument pickup systems

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0527654A2 (en) * 1991-08-14 1993-02-17 Fernandes Co., Ltd. An electric stringed instrument having a device for sustaining the vibration of the string

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2013079844A1 *

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