Classifications

• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC 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
  • G10H3/00—Instruments in which the tones are generated by electromechanical means
  • G10H3/12—Instruments 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
  • G10H3/14—Instruments 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
  • G10H3/18—Instruments 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
  • G10H3/181—Details of pick-up assemblies
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC 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
  • G10H3/00—Instruments in which the tones are generated by electromechanical means
  • G10H3/12—Instruments 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
  • G10H3/14—Instruments 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
  • G10H3/18—Instruments 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
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING 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
  • G01D5/00—Mechanical 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
  • G01D5/12—Mechanical 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
  • G01D5/14—Mechanical 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
  • G01D5/20—Mechanical 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
  • G01D5/22—Mechanical 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
  • G01D5/225—Mechanical 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
  • G01D5/2275—Mechanical 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
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10H—ELECTROPHONIC 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
  • G10H2220/00—Input/output interfacing specifically adapted for electrophonic musical tools or instruments
  • G10H2220/461—Transducers, 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
  • G10H2220/505—Dual 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.

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• 2011
  • 2011-12-02 FR FR1161074A patent/FR2983621B1/fr not_active Expired - Fee Related
• 2012
  • 2012-11-09 US US14/362,329 patent/US9286873B2/en not_active Expired - Fee Related
  • 2012-11-09 WO PCT/FR2012/052588 patent/WO2013079844A1/fr active Application Filing
  • 2012-11-09 CA CA2858035A patent/CA2858035A1/fr not_active Abandoned
  • 2012-11-09 EP EP12801619.3A patent/EP2786372A1/de not_active Withdrawn

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