• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    This device for controlling a loudspeaker (14) in an enclosure comprises: an input for an audio signal to be reproduced; a supply output of an excitation signal of the loudspeaker; means (26, 36, 38, 70, 71, 80, 90) for calculating, at each instant (t), at least one predicted current (iref (t)) for the excitation signal of the loudspeaker ( 14) according to the audio signal. It comprises an attenuator (71) adapted to limit the predicted current to a limited current value lower than a ceiling value per application, to the predicted current of attenuation gain which is a function of the predicted current.
    公开号:FR3031854A1
    申请号:FR1550413
    申请日:2015-01-19
    公开日:2016-07-22
    发明作者:Eduardo Mendes；Frederic Lepoutre；Pierre-Emmanuel Calmel
    申请人:Devialet SA；
    IPC主号:
    专利说明:

    [0001] The present invention relates to a device for controlling a loudspeaker in an enclosure comprising: an input for an audio signal to be reproduced; a supply output of an excitation signal of the loudspeaker; means for calculating, at each moment, at least one predicted current for the excitation signal of the loudspeaker as a function of the audio signal. Most often the speakers are powered from the amplifier.
    [0002] From the sound signal to be broadcast, a voltage amplifier applies a voltage to the loudspeaker proportional to the sound signal to be reproduced. The proportionality gain is given by the user's desired volume gain and the gain in voltage of the amplifier. The current flowing in the loudspeaker, delivered by the amplifier, depends on the impedance of the loudspeaker. The instantaneous amplitude limitation of this current may be necessary to protect the amplifier and / or the loudspeaker. This limitation must be achieved without introduction of audible artifacts of the audible signal broadcast by the loudspeaker. The methods proposed in the state of the art are most often based on a combination of active and / or passive electronic circuits. The passive circuits are not adjustable, do not allow a fine adjustment of the device and are subject to variations during operation. The operating principle of these active and / or passive circuits consists, most often, in introducing a resistive element in series with the loudspeaker in order to reduce the current, thus introducing additional losses in the system. This type of method requires the installation of additional electronic elements in the installation, thus making it more expensive, more voluminous and susceptible to breakdowns. Methods are based on a model of the loudspeaker, from the voltage applied to the loudspeaker, estimate the current of the loudspeaker, then by comparing this current with a predefined threshold, reduce the voltage applied to the top if the current exceeds this threshold. This method suffers from two difficulties. First of all, the loudspeaker is a complex electromechanical dynamic system and the threshold is complex to define. Then, under certain conditions, decreasing the voltage applied to the loudspeaker will have the effect of increasing the instantaneous current and not reducing it.
    [0003] Devices for limiting the voltage applied to the loudspeaker or the displacement of the speaker diaphragm are widely described in the literature. These are devices called compressors (attenuators), for the direct limitation in amplitude, or devices using variable frequency filters controlled by the magnitude to be limited, for the indirect limitation in amplitude. The limitation of the current therefore imposes either a current sensor or means for estimating the current from the voltage and devices for limiting the voltage applied to the loudspeaker. These devices are relatively complex and affect the quality of the sound reproduction, correcting the voltage applied to the speaker. The invention aims to provide a satisfactory control of a speaker, limiting the current applied to the speaker that is simple to implement.
    [0004] For this purpose, the subject of the invention is a device for controlling a loudspeaker of the aforementioned type, characterized in that it comprises an attenuator capable of limiting the predicted current to a limited current value less than a ceiling value. by application, to the predicted current of an attenuation gain which is a function of the predicted current.
    [0005] According to particular embodiments, the control device comprises one or more of the following characteristics: the attenuator is capable of applying an attenuation gain of between 0 and 1 and which tends to 1 when the value of the limited current is below the ceiling value; the attenuation gain satisfies the relations: If ref (t) I> in, ax (t) then gatt (t) = in ,, x (t) / Iiref (t) If ref (1) I n, , x (t) then gatt (t) = gatt (t-Ts) + kx (1-gatt (t-Ts)) where gatt (t-Ts) is the value of the attenuation gain at the previous calculation step , Ts being the time between two successive calculations k is a constant in 10.1 ['x (t) is the ceiling value for the current iref (t) is the predicted value for the current. Said device comprises means for calculating the voltage to be applied from the current to be applied and the voltage to be applied depends on the value of the limited current; said device comprises, upstream of the means for calculating the predicted current, a desired model capable of applying a filtering function defining the ratio of the amplitude of a desired signal to the amplitude of the input signal coming from the module; Depending on the frequency and the desired model is able to modify the function as a function of filtering the predicted current; the filtering function is such that, for frequencies lower than a cut-off frequency, the ratio of the amplitudes is a function converging towards zero when the frequency tends to zero and the desired model is able to modify the cutoff frequency as a function of the predicted current; the desired model comprises a filter centered on a predetermined frequency suitable for reducing the current in a desired frequency band around the predetermined frequency; the desired model is able to modify the gain of the filter as a function of the predicted current.
    [0006] The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings, in which: FIG. 1 is a diagrammatic view of a sound reproduction installation; FIG. 2 is a curve illustrating a desired model of sound reproduction for the installation; FIG. 3 is a schematic view of the loudspeaker control unit; FIG. 4 is a detailed schematic view of the structural adaptation unit; FIG. 5 is a detailed schematic view of the unit for calculating reference dynamic quantities; FIG. 6 is a view of a circuit representing the mechanical modeling of the loudspeaker with a view to its control in an enclosure equipped with a vent; FIG. 7 is a view of a circuit representing the electrical modeling of the loudspeaker with a view to its control; FIG. 8 is a flowchart of the current limiting algorithm circulating in the speaker coil; FIG. 9 is a schematic view of a first embodiment of the open loop estimation unit of the loudspeaker resistor; FIG. 10 is a view of a circuit of the thermal model of the loudspeaker; FIG. 11 is a view identical to that of FIG. 9 of an alternative embodiment of the closed loop estimation unit of the loudspeaker resistor; and FIG. 12 is a view identical to that of FIG. 6 of another embodiment for an enclosure provided with a passive radiator. The sound reproduction installation 10 illustrated in FIG. 1 comprises, as known per se, a module 12 for producing an audio signal, such as a digital disk player connected to a loudspeaker 14 of a loudspeaker. 16 between the audio source 12 and the amplifier 16is disposed a control unit 18 comprising, successively in series, a desired model 20, corresponding to the desired model of behavior of the enclosure, and a device 22. This desired model is linear or nonlinear. According to a particular embodiment, a loop 23 for measuring a physical quantity, such that the temperature of the magnetic circuit of the loudspeaker or the current flowing in the coil of the loudspeaker is provided between the loudspeaker 14 and the control device 22. The desired model 20 is independent of the speaker used in the installation and its modeling. The desired model 20 is, as illustrated in FIG. 2, a function expressed as a function of the frequency of the ratio of the amplitude of the desired signal noted S'clio ref on the amplitude S'dio of the input signal coming from the module Advantageously, for frequencies lower than a cut-off frequency Gin, this ratio is a function converging towards zero when the frequency tends to zero, to limit the reproduction of the excessively low frequencies and thus to avoid displacements of the speaker's membrane. out of the ranges recommended by the manufacturer. It is the same for high frequencies where the ratio tends to zero beyond a frequency f'x when the frequency of the signal tends to infinity. The desired model is able to modify continuously, that is to say at each computation step of the control device, the minimum cut-off frequency fmin, as a function of a predicted intensity iref provided by the control device 22 to through a link 23B as will be described later, especially with reference to FIG. 8. The control device 22, the detailed structure of which is illustrated in FIG. 3, is arranged at the input of the amplifier 16. This device is capable of receiving as input the audio signal S'clio ref to be reproduced as defined in FIG. outputting the desired model 20 and outputting a signal Uref, forming an excitation signal of the loudspeaker which is provided for amplification to the amplifier 16. This signal Uref is adapted to take account of the non-linearity of the top The control device 22 comprises means for calculating different quantities as a function of the values of derivatives or integrals of other quantities defined at the same times. For computational requirements, the values of the unknown quantities at the instant n are taken equal to the corresponding values of the instant n-1. The values of the instant n1 are preferably corrected by a prediction with the order 1 or 2 of their values using the derivatives of higher orders known at time n-1.
    [0007] According to the invention, the control device 22 implements a control using in part the principle of the differential flatness which makes it possible to define a reference control signal of a differentially flat system from sufficiently smooth reference paths.
    [0008] As illustrated in FIG. 3, the control module 22 receives as input the audio signal S'clio ref to be reproduced from the desired model 20. A unit 24 for applying a unit conversion gain, depending on the voltage peak of the amplifier 16 and a variable attenuation between 0 and 1 controlled by the user, ensures the passage of the reference audio signal Ded ret to a yo signal, image of a physical quantity to reproduce. The signal yo is, for example, an acceleration of the air opposite the loudspeaker or a speed of the air to be displaced by the loudspeaker 14. In the following, it is assumed that the signal yo is the acceleration of the air set in motion by the enclosure. At the output of the amplification unit 24, the control device comprises a unit 25 for structural adaptation of the signal to be reproduced as a function of the structure of the enclosure in which the loudspeaker is used. This unit is able to provide a reference variable Aret desired at each instant for the speaker membrane from a corresponding quantity, here the signal yo, for the movement of the air set in motion by the enclosure comprising the speaker. Thus, in the example under consideration, the reference quantity Aret, calculated from the acceleration of the air to be reproduced yo, is the acceleration to be reproduced for the speaker membrane so that the operation of the loudspeaker impose on the air an acceleration yo. FIG. 4 shows a detail of the structural adaptation unit 25. The input y 0 is connected to a bounded integration unit 27 whose output is itself connected to another bounded integration unit 28.
    [0009] Thus, at the output of the units 27 and 28 are obtained respectively the first integral vo and the second integral xo of the acceleration Yo. The bounded integration units are formed of a first-order low-pass filter and are characterized by a FogF cutoff frequency. The use of bounded integration units allows the quantities used in the control device 22 to be the derivatives or the integrals of each other only in the useful bandwidth, ie for the higher frequencies. at the FoeF cutoff frequency. This makes it possible to control the excursion at low frequency of the quantities considered. In normal operation, the cutoff frequency FoBF is chosen so as not to influence the signal at the low frequencies of the useful bandwidth.
    [0010] The cut-off frequency FogF is taken less than one-tenth of the frequency f ,,, of the desired model 20. In the case of a vent enclosure in which the loudspeaker is mounted in a case opened by a vent, the unit 25 produces the desired reference acceleration for the Aret membrane by the following relation: Km2 Km2 Aref = YD = Yo + Rm2 vo + mm2) c0 With: Rm2: coefficient of acoustic leakage of the enclosure; Mm2: inductance to the air mass in the vent; Km2: stiffness of the air in the enclosure. xo: position of the total air displaced by the diaphragm and the vent dr ° Vo = -dt: speed of the total air displaced by the diaphragm and the vent dvo yo = -dt: acceleration of the total air displaced . In this case, the desired reference acceleration for the Aret membrane is corrected for structural dynamic magnitudes x o, v, of the enclosure, the latter being different from the dynamic quantities relating to the speaker membrane. This reference quantity Aret is introduced into a calculation unit 26 of reference dynamic quantities capable of providing, at each moment, the value of the derivative with respect to the time of the reference variable denoted dAref / dt as well as the values of the integrals. first and second with respect to the time of this reference variable noted respectively Vref and Xref. The set of reference dynamic quantities is noted in the Gref suite. FIG. 5 illustrates a detail of the computing unit 26. The input Aret is connected to a branching unit 30 on the one hand and to a bounded integration unit 32 on the other hand whose output is it -connected to another bounded integration unit 34.
    [0011] Thus, at the output of the units 30, 32 and 34 are respectively obtained the derivative of the acceleration dArevdt, the first integral Vref and the second integral Xref of the acceleration. The bounded integration units are formed of a first-order low-pass filter and are characterized by a FogF cut-off frequency. The use of bounded integration units allows the quantities used in the control device 22 to be the derivatives or the integrals of each other only in the useful bandwidth, ie for the higher frequencies. at the FoeF cutoff frequency. This makes it possible to control the excursion at low frequency of the quantities considered.
    [0012] In normal operation, the cutoff frequency FoBF is chosen so as not to influence the signal at the low frequencies of the useful bandwidth. The cutoff frequency FogF is taken less than one tenth of the frequency f ,,, of the desired model 20.
    [0013] The control device 22 comprises, in a memory, a table and / or a set of electromechanical parameter polynomials 36 as well as a table and / or a set of polynomials of the electrical parameters 38. These tables 36 and 38 are suitable for defining , according to the dynamic reference values G ref received at the input, the electromechanical parameters Pmé 'and electrical Pélec lec respectively. These parameters Pmé 'and Pé are obtained respectively from a mechanical modeling of the loudspeaker as illustrated in FIG. 6, where the loudspeaker is supposed to be installed in a vent enclosure, and an electrical modeling of the The electromechanical parameters Pmé 'include the magnetic flux picked up by the coil noted BI produced by the magnetic circuit of the HP, the stiffness of the speaker noted Kmt (xD), the mechanical friction, as shown in FIG. Rie loudspeaker rated loudspeaker, the moving mass of the loudspeaker noted Mmt, the stiffness of the air in the enclosure rated Km2, the acoustic leakage of the enclosure rated Rm2 and the air mass in the event rated Mm2. The modeling of the mechanico-acoustic part of the loudspeaker placed in a vent enclosure illustrated in FIG. 6 comprises, in a single closed-loop circuit, a voltage generator 40 BI (xD, i) .i corresponding to the force motor generated by the current flowing in the coil of the loudspeaker. The magnetic flux BI (xD, i) depends on the position xi, the membrane as well as the intensity i flowing in the coil. This modeling takes into account the viscous mechanical friction FU of the membrane corresponding to a resistor 42 in series with a coil 44 corresponding to the overall moving mass Mmt of the membrane, the stiffness of the membrane corresponding to a capacitor 46 of capacitance Cmt (xD) equals 1 / Kmt (xD). Thus, the stiffness depends on the xD position of the membrane. To account for the vent, the following parameters Rm2, Cm2 and Mm2 are used: Rm2: coefficient of acoustic leakage of the enclosure; Mm2: inductance equivalent to the air mass in the vent; Cm2 =: compliance of the air in the enclosure. In the modeling of FIG. 6, they respectively correspond to a resistor 47, a coil 48 and a capacitor 49 connected in parallel.
    [0014] In this model, the force resulting from the reluctance of the magnetic circuit is neglected.
    [0015] The variables used are: vD = -cxtp: speed of the dvD speaker diaphragm yD = -dt: acceleration of the speaker diaphragm vL: air speed of the air leaks vp: speed of the speaker air out of the vent (port) vo = -dxo = vD + 12L + Vp total air speed moved by the merlin: ria. ne and the vent dt yo = -dvo: acceleration of the total air moved. dt The total sound pressure at 1 meter is given by: p = Psi) yo where SD: loudspeaker cross-section, nstr = 2: solid emission angle.
    [0016] The mechanico-acoustic equation corresponding to FIG. 10 is as follows: dvD B1 (xD, i) i = Mnit-dt + RnitvD + Knit (xD) xD + Kni2x0 Km2 Km2 The following relation links the different quantities: yo = yD - vo - mm2 X0 Rm2 The modeling of the electrical part of the loudspeaker is illustrated in FIG. 7. The electrical parameters P elec include the inductance of the coil Le, the para-inductance L2 of the coil and the loss-iron equivalent. R2.
    [0017] The modeling of the electrical part of the loudspeaker illustrated in FIG. 7 is formed of a closed-loop circuit. It comprises a generator 50 of electromotive force ue connected in series with a resistor 52 representative of the resistor Re of the coil of the loudspeaker. This resistor 52 is connected in series with an inductance Le (xD, i) representative of the inductance of the coil of the loudspeaker. This inductance depends on the intensity i flowing in the coil and the xD position of the membrane. To account for magnetic losses and variations in inductance due to the effect of eddy currents, a parallel circuit RL is connected in series at the output of the coil 54. A resistor 56 of value R2 (xD, i) depending on the position of the the xD membrane and intensity i flowing in the coil is representative of the loss-iron equivalent. Similarly, a coil 58 of inductance L2 (xD, i) also depends on the xD position of the membrane and the intensity i flowing in the circuit is representative of the para-inductance of the loudspeaker. Also connected in series in the modeling, a voltage generator 60 producing a voltage BI (xD, i) .v representative of the counter-electromotive force of the moving coil in the magnetic field produced by the magnet and a second generator 62 producing a voltage g (xD, i) .v with g (xD, i) = idLe (xD'i) representative of dxD the effect of the dynamic variation of the inductance with the position.
    [0018] In general, we notice that, in this modelization, the flux BI picked up by the coil, the stiffness Kmf and the inductance of the coil Le depend on the position xi, of the membrane, the inductance Le and the flow BI depend on also current i flowing in the coil.
    [0019] Preferably, the inductance of the coil Le, the inductance L2 and the term g depend on the intensity i, in addition to depending on the displacement xi, of the membrane. From the modelings explained with regard to FIGS. 6 and 7, the following equations are defined: ## EQU1 ## - i 2) dt B1 (xD, i) i = Ittv D + Mt + K t (x D) x D + K 0 dt The control module 22 further comprises a unit 70 for calculating the reference current iref and This unit receives as input the reference dynamic variables Gref, the mechanical parameters Pmeca, and the magnitudes xo and vo.
    [0020] This calculation of the reference current Iref and its derivative dIref / dt satisfies the two equations: (x'f, i'f) i'f = Rmtv'f + M A'f + K tnt (x 'f) x' f + K 0 d - (G1 (xref iref) iref Rmt Aref Mmt dAref I dt + Kmt (xref) 1) ref Km2V0 dt 1 dL e (x ref ref) with Gi (xref, iref) = B1 (x ref ref ) - - i ref 2 dx Thus, the current iref and its derivative tellf / dt are obtained by an algebraic calculation from the values of the vectors entered by an exact analytical calculation or a numerical resolution if necessary according to the complexity of Gi ( x, i). The derivative of the current sayf / dt is thus obtained preferably by an algebraic calculation or otherwise by numerical derivation.
    [0021] In order to avoid deterioration of the loudspeaker 14, by circulating too much current, the control unit 18 comprises, on the one hand, means for modifying the function of the desired model 20 as a function of the current iref (t) predicted by the control device 22 transmitted through the connection 23B and, secondly, a current compression unit 71 iref adapted to maintain the current iref (t) at the output of the unit 71 to a value, ref, applied (t) less than a maximum limit value, (t). The means for modifying the function of the desired model and the compression unit 71 are implemented in combination or only one of them is implemented.
    [0022] The compression unit 71 forms an attenuator by applying an attenuation gain gatt (t). It is provided at the output of the current calculation unit 70 as illustrated in FIG. 3. For the limitation of the current iref (t) and therefore the calculation of the current (i vref) applied (t), the algorithm of the FIG. 8 is implemented by the control unit 18.
    [0023] During a step 72, the current iref (t) predicted by the reference current calculation unit 70 is supplied to the desired model 20 and the compression unit 71. This current depends on the time as explained previously. It is provided for each calculation step of the unit 70. In step 73, the current iref (t) is compared to a fraction g.imax (t) of the maximum permissible current imax (t) by the loudspeaker . The coefficient g is a value between 0 and 1 set during the design of the unit 18. If the reference current iref (t) is greater than g.imax (t), then the desired model 20 is modified, in particular by gradually increasing the minimum cutoff frequency f ,,, of the desired model shown in Figure 2. The desired model is modified in step 74 gradually with a relatively slow speed to make inaudible changes in cutoff frequency. Thus, in the example considered, the minimum frequency f ,,, is increased by a value Af at each calculation step of a new value iref (t) by the control unit 22. In a variant, the desired model 20 comprises a filter centered on a predetermined frequency (known as the peak-notch in English language) adapted to reduce the current in a desired frequency band around the predetermined frequency. In this case, the gain of the filter is adjusted in the desired frequency band as a function of the reference current iref (t). In step 74, the gain of the filter is incrementally decreased at a speed determined so as to render inaudible the gain variations of the filter. According to the invention, a variation of the minimum cut-off frequency f ,,, and a variation of the gain of the filter are implemented simultaneously or independently of one another according to the embodiment implemented. In step 75, the value of the reference current iref (t) is compared with the maximum current value imax (t).
    [0024] If iref (t) is greater than m '(t), an attenuation gain gatt (t) is calculated in step 76. The attenuation gain gatt (t) is given by the formula gatt (t) = im '(t) / Iiref (t) In the following step 77, the limited reference current value h, ref, 1 applied (1) is calculated as the product of the attenuation gain gatf (t) previously calculated by the reference current iref (t) by the formula (iref) applied (t) = gatt (t) X Gee) The reference current value, ref, applied (1) is used subsequently for the calculation of the voltage Uref reference output which will be amplified and applied to the terminals of the loudspeaker 14.
    [0025] At the end of step 77, step 72 is again implemented with the new reference current iref (t) predicted in the next step by the control device 22. At step 73, if the value of the reference current iref (t) is less than gimax (t), then step 78 aiming at reducing the cutoff frequency of the desired model is implemented, if during the test carried out in step 78A, the frequency current cut fm, n is greater than a nominal frequency f -norninal- Step 78, opposite to step 74 of increasing the minimum cutoff frequency, subtracts at the current cutoff frequency fm, n the increment Af able to ensure a gradual lowering of the cutoff frequency, as long as the reference current remains below the fraction of the maximum current gimax (t) and the cutoff frequency fm, n has not reached its nominal value f - norninale- In an embodiment where the gain of a filter is changed at step 74, the gain of the filter is increased by one step in step 78. At the end of step 78 or if the test of step 78A is negative, a new attenuation gain gatf (t) is calculated in step 79 from the previous attenuation gain gatt (t-Ts) calculated during the previous step to allow a gradual rise in gain at a speed dependent on a parameter k. The gain gatf (t) is calculated according to the formula: gatt (t) = gatf (tT) + kx (1 - gaff (t-Ts)) where gatt (t-Ts) is the value of the gain of attenuation at step previous calculation, Ts being the time between two successive calculations k is a constant in 10.1 [imax (t) is the ceiling value for the current iref (t) is the predicted value for the current. This same step 79 is carried out if, after the test of step 75, the reference current iref (t) is lower than the current imax (t). After calculating the new attenuation gain gatt (t), a new calculation of the reference current applied iref (t) is conducted at step 77 from the new attenuation gain. It is conceivable that the predictive calculation of the reference current iref (t) allows this reference current to be taken into account for the modification of the desired model, and for the calculation of a value of an applied limit reference current (i, ref) applied (t) limited to prevent the circulation of too much current in the speaker 14. The presence of the compression unit 71 applied to the reference current iref avoids the implementation of a sensor current as well as the implementation of elements adapted to reduce the voltage of the speaker 14 by an additional resistor.
    [0026] In addition, the control device 22 comprises a unit 80 for estimating the resistor Re of the loudspeaker. This unit 80 receives as input the reference dynamic variables Gref, the intensity of the reference currents (r and) applied and its derivative dli, ref, applied / dt and, according to the embodiment envisaged, the temperature measured on the circuit Magnet of the loudspeaker denoted T, measured or the intensity measured through the measured coil measured. In the absence of measurement of the circulating current, the estimation unit 80 is of the form illustrated in FIG. comprises at input a module 82 for calculating the power and parameters and thermal model 84. The thermal model 84 calculates the resistance Re from the calculated parameters, the determined power and the measured measured temperature. 10 gives the general scheme used for the thermal model. In this model, the reference temperature is the internal air temperature of the enclosure Te. The temperatures considered are: Tb [° C]: winding temperature; Tm [° C]: temperature of the magnetic circuit; and Te [° C]: internal temperature of the enclosure assumed constant or, ideally, measured. The thermal power considered is: PJb [W]: thermal power supplied to the winding by Joule effect; The thermal model comprises, as illustrated in FIG. 9, the following parameters: Ctbb [J / K]: heat capacity of the winding; Rthbm [K / WI: equivalent thermal resistance between the winding and the magnetic circuit; and Rthba [K / VV]: equivalent thermal resistance between the winding and the internal temperature of the enclosure; The equivalent thermal resistances take into account the heat dissipation by conduction and convection.
    [0027] The thermal power Pjb supplied by the current flowing in the winding is given by: Pjb (t) = Re (Tb) i2 (t) where Re (Tb) is the value of the electrical resistance at the temperature Tb: Re (Tb) - Re (20 ° C) x (1+ 4.10-3 (Tb - 20 ° C)) where Re (20 ° C) is the value of the electrical resistance at 20 ° C. The thermal model given in FIG. 9 is the following: dTb 1 1 C thb) (Tm Tb) ± (Te - Tb) ± Pjb ut-nrbbm (X ref RthbakVref I Its resolution makes it possible to obtain the value of the resistance Re every moment.
    [0028] In a variant, as illustrated in FIG. 11, when the current i flowing in the coil is measured, the estimate of the resistance Re is ensured by a closed-loop estimator, for example of integral proportional type. This makes it possible to have a fast convergence time thanks to the use of an integral proportional corrector. Finally, the control device 22 comprises a unit 90 for calculating the reference output voltage Uref, based on the reference dynamic variables Gref, the applied reference current (i -ref) applied and its derivative d (i -ref) applied / dt, electrical parameters P - elec and resistance Re calculated by the unit 80. This unit for calculating the reference output voltage uses the following two equations: For reasons of simplification, ref, applied is noted iref in the following expressions L2 (Xrefref) of 2 di ,. U2 ± = L2 (X i) R2 (x) dt ref ref dt di 'f dLe (x'f, i'f) uref + The (Xrefiref Vref dt + u2 + BI (xrefiref) vref + iref dt g ( x'f, i) In the case where the amplifier 16 is an amplifier in current and not in voltage as previously described, the units 38, 80 and 90 of the control device are suppressed and the reference output intensity iref commander the amplifier is taken at the output of the unit 70. In the case of an enclosure comprising a passive radiator formed of a membrane, the mechanical model of FIG. 6 is replaced by that of FIG. 12 in which the identical elements those in Figure 6 carry the same reference numbers.
    [0029] This module comprises in series with the coil Mm2 48, corresponding to the mass of the passive radiator membrane, a resistor 202 and a capacitor 204 of value 1 Cm3 = -K respectively correspond to the mechanical losses Rm2 of the passive radiator and the mechanical stiffness Km3 of the passive radiator membrane. The reference acceleration of the Aret membrane is given by: Km2 Km2 A 'f = yo + Vo + 1m2 with XOR given by filtering by a high-pass filter of xo: s2 XOR = X0 S2 + Irt3RAI KA, r3 -m2 Thus, the structural adaptation structure 25 will comprise in series two bounded integrators for obtaining vo and xo from yo, then the calculation of XOR from xo by high-pass filtering with the additional parameters Rm3 and Km3 which are, respectively, the mechanical loss resistance and the mechanical stiffness constant of the passive radiator membrane. XOR
    权利要求:
    Claims (8)
    [0001]
    CLAIMS1.- Control device of a loudspeaker (14) in a chamber comprising: - an input for an audio signal (S'a, o) to be reproduced; a supply output of an excitation signal of the loudspeaker; means (26, 36, 38, 70, 71, 80, 90) for calculating, at each instant (t), at least one predicted current (iref (t)) for the excitation signal of the loudspeaker ( 14) according to the audio signal (S'a, o); characterized in that it comprises an attenuator (71) adapted to limit the predicted current (Gee)) to a limited current value ((lref) applied) lower than a ceiling value (Imax (t)) per application, to the current predicts (iref (t)) an attenuation gain (gatt (t)) which is a function of the predicted current (Iref (t)).
    [0002]
    2.- Device according to claim 1, characterized in that the attenuator (71) is adapted to apply an attenuation gain (gatt (t)) of between 0 and 1 and which tends to 1 when the limited current value is less than the ceiling value (Imax (t)).
    [0003]
    3.- Device according to claim 2, characterized in that the attenuation gain (gatt (t)) satisfies the relations: If ref (t) I> in, ax (t) then gatt (t) = in, ax (t) / Iiref (t) If ref (t) I max (t) then gatt (t) = gatt (t-Ts) + kx (1 - gatt (t-Ts)) where gatt (t-Ts) is the value of the attenuation gain at the previous calculation step, Ts being the time separating two successive calculations k is a constant in 10.1 [imax (t) is the ceiling value for the current iref (t) is the predicted value for the current.
    [0004]
    4.- Device according to any one of the preceding claims, characterized in that it comprises means (80) for calculating the voltage (Uref) to be applied from the current (GO)) to be applied and that the The voltage (Uref) to be applied depends on the value of the limited current ((lref) applied (t)).
    [0005]
    5.- Device according to any one of the preceding claims, characterized in that it comprises, upstream means (26, 36, 38, 70, 71, 80, 90) for calculating the predicted current (4), a desired model (20) adapted to apply a filter function defining the ratio of the amplitude of a desired signal (S'dio ref) to the amplitude (S'd, o) of the input signal from the module (12) as a function of the frequency and in that the desired model (20) is capable of modifying the function as a function of filtering the predicted current (iref (t)).
    [0006]
    6.- Device according to claim 5, characterized in that the filtering function is such that, for frequencies below a cutoff frequency (fmin), the ratio of the amplitudes is a function converging to zero when the frequency tends to zero and in that the desired model (20) is capable of modifying the cutoff frequency (fmin) as a function of the predicted current (iref (t)).
    [0007]
    7.- Device according to claim 5 or 6, characterized in that the desired model (20) comprises a filter centered on a predetermined frequency adapted to reduce the current in a desired frequency band around the predetermined frequency.
    [0008]
    8.- Device according to claim 7, characterized in that the desired model (20) is adapted to change the gain of the filter according to the predicted current (iref (t)).
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    WO2016116435A1|2016-07-28|
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    FR3031854B1|2017-02-17|
    KR20170140155A|2017-12-20|
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    法律状态:
    2015-12-24| PLFP| Fee payment|Year of fee payment: 2 |
    2016-07-22| PLSC| Publication of the preliminary search report|Effective date: 20160722 |
    2017-01-05| PLFP| Fee payment|Year of fee payment: 3 |
    2017-12-22| PLFP| Fee payment|Year of fee payment: 4 |
    2019-12-12| PLFP| Fee payment|Year of fee payment: 6 |
    2020-12-30| PLFP| Fee payment|Year of fee payment: 7 |
    2021-12-10| PLFP| Fee payment|Year of fee payment: 8 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1550413A|FR3031854B1|2015-01-19|2015-01-19|DEVICE FOR CONTROLLING A LOUDSPEAKER WITH CURRENT LIMITATION|FR1550413A| FR3031854B1|2015-01-19|2015-01-19|DEVICE FOR CONTROLLING A LOUDSPEAKER WITH CURRENT LIMITATION|
    US15/544,808| US10448155B2|2015-01-19|2016-01-19|Device for controlling a loudspeaker with current limitation|
    KR1020177023147A| KR20170140155A|2015-01-19|2016-01-19|Device for controlling loudspeaker using current limit|
    CA2974131A| CA2974131A1|2015-01-19|2016-01-19|Device for controlling a loudspeaker with current limitation|
    BR112017015371-8A| BR112017015371A2|2015-01-19|2016-01-19|? control device of a speaker?|
    JP2017537942A| JP2018507608A|2015-01-19|2016-01-19|Device for controlling loudspeakers with current limiting|
    CN201680012947.1A| CN107431466A|2015-01-19|2016-01-19|Pass through the equipment of current limit controlling loudspeaker|
    PCT/EP2016/050995| WO2016116435A1|2015-01-19|2016-01-19|Device for controlling a loudspeaker with current limitation|
    EP16701002.4A| EP3248285A1|2015-01-19|2016-01-19|Device for controlling a loudspeaker with current limitation|
    JP2021204275A| JP2022036118A|2015-01-19|2021-12-16|A device for controlling loudspeakers by current limitation|
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