CN102118678B - Method and system for measuring speaker parameters by using current sensor - Google Patents
Method and system for measuring speaker parameters by using current sensor Download PDFInfo
- Publication number
- CN102118678B CN102118678B CN201110083837.3A CN201110083837A CN102118678B CN 102118678 B CN102118678 B CN 102118678B CN 201110083837 A CN201110083837 A CN 201110083837A CN 102118678 B CN102118678 B CN 102118678B
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- digital
- loud speaker
- module
- 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.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 41
- 230000004044 response Effects 0.000 claims abstract description 65
- 238000006073 displacement reaction Methods 0.000 claims abstract description 41
- 238000005086 pumping Methods 0.000 claims description 50
- 238000005259 measurement Methods 0.000 claims description 32
- 238000006243 chemical reaction Methods 0.000 claims description 28
- 238000012545 processing Methods 0.000 claims description 14
- 238000005070 sampling Methods 0.000 claims description 12
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 10
- 230000005284 excitation Effects 0.000 claims description 5
- 230000003595 spectral effect Effects 0.000 claims description 3
- 230000007704 transition Effects 0.000 claims description 3
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 238000012360 testing method Methods 0.000 abstract description 5
- 238000005516 engineering process Methods 0.000 abstract description 2
- 238000001514 detection method Methods 0.000 abstract 1
- 230000008859 change Effects 0.000 description 7
- 238000013461 design Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 238000012546 transfer Methods 0.000 description 4
- 238000012372 quality testing Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000003908 quality control method Methods 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 241000978750 Havardia Species 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000005094 computer simulation Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
Abstract
The invention provides a method for measuring speaker parameters by using a current displacement sensor, and provides a test system for implementing the method. The method comprises the following steps: exciting a measured device by adopting a stepping swept-frequency signal; measuring voltage signals at the two ends of the measured device as well as a current response signal flowing through the measured device at the same time; and substituting the signals into a linear module and a large-signal Volterra model of the speaker, and acquiring linear parameters and non-linear parameters of the speaker through system identification. The method does not need a laser sensor, the cost is low, and the non-linear parameter identification technology of the speaker can be applied to the production detection of speaker products.
Description
Technical field
The invention belongs to measurement method of parameters and the measuring system of loud speaker, specifically by loudspeaker wiring terminal voltage and load current are carried out to Nonlinear Systems Identification, obtain the method and system of a plurality of parameters of electro-acoustic product
.can be widely used in the speaker product quality testing and end product of electroacoustic enterprise.
Background technology
The meaning that loudspeaker parameters is measured:
Loudspeaker parameters has important effect to the design of loud speaker, manufacture and quality control.Since 1970, the T/S parameter that the A. N. Thiele of Australia and R. H. Small have proposed speaker system, makes the design that realizes speaker system by filter synthesis method become possibility.Small-signal parameter is wherein in the negligible situation of distortion, to record in small signal driving, system output, therefore claim again linear dimensions.This parameter can be used for characterizing the low frequency performance of loud speaker, should be in the design of loud speaker and the quality control of production.
Since 1980, researcher starts the large-signal performance of loud speaker to carry out various quantitative analysiss.Many models are used to the Analysis of Nonlinear Characteristics of loud speaker, as Volterra model (Volterra), state-space model, finite element and boundary element model, Hammerstein and Wiener model etc.By loud speaker modeling and large signal parameters are measured, can set up the computer model of tested speaker, in the design phase of loud speaker, can understand the expection electroacoustic performance of this design, in the small lot pilot stage, can measure the parameter of sample with checking and modification design, can be for accident analysis and process modification in the volume production stage.
The measurement of the parameter measurement of loud speaker, particularly nonlinear parameter is a difficult problem for electroacoustic measurement circle, and measuring technique and the method for existing linear dimensions and nonlinear parameter are as follows:
1) by changing the method for diaphragm mass, cavity volume: measure the impedance operator of loud speaker, thereby obtain
f s ,
q ts etc. parameter, utilize afterwards additional mass or additional volume method again to measure impedance operator, thereby obtain
f s ',
q ts ' etc., and calculate all linear dimensions.This method shortcoming is: 1, generally need double measurement, troublesome poeration; 2, additional mass or additional volume method have been destroyed the original operating state of loud speaker to a certain extent, therefore result is inaccurate; 3, double measurement causes vibrating diaphragm compliance, voice coil temperature to change, and measurement result is had to impact.
2) by measuring the method for acoustic pressure, current response: United States Patent (USP) 6269318 (Method For determining
Transducer linear operation parameters) method that use voltage-acoustic pressure transfer function and electric current-acoustic pressure transfer function are measured linear parameter of loudspeaker has been proposed.The microphone that the method is used is subject to ambient noise, ambient temperature and humidity impact, and the method need to provide the condition of the test casing of a known volume as Measurement accuracy simultaneously.
3) by changing equilbrium position, measure: openly patent of invention CN200510041525.0 is (based on raising of System Discrimination
Sound device unit method for measuring non-linear parameters) use the method for the adjustable DC electric current of feeding to make voice coil loudspeaker voice coil be offset certain position, under different voice coil loudspeaker voice coil displacements, measure impedance, and anti-Model Distinguish obtains nonlinear parameter according to loudspeaker unit nonlinear resistance.The method need to be used adjustable DC source to loud speaker output offset electric current, and this electric current can make voice coil temperature rise.In addition the equilbrium position due to vibrating diaphragm changes, and speaker operation is at special state.Also have scholar to propose to use cavity and air pump to change the method for vibrating diaphragm equilbrium position, but equipment needed thereby is comparatively special, also has the problem that changes loud speaker normal operating conditions simultaneously.
4) use laser sensor to measure the displacement of the diaphragm of loudspeaker.First, laser measurement is non-cpntact measurement, and without the equilbrium position, quality etc. that change vibrating diaphragm, speaker operation is in normal condition; Secondly, laser measurement is not affected by noise, and it is little that laser sensor is affected by humiture.Yet under production line environment, or in speaker system product, use laser sensor to need special support, need to guarantee environment friction interference etc., these condition restriction its can only be applied in research and development and small lot quality testing.
Summary of the invention
The present invention is directed to above-mentioned deficiency, propose a kind of method and system of using current sensor measurement loud speaker linearity and nonlinear parameter
.
The use current sensor measurement loud speaker linearity that the present invention proposes and the method for nonlinear parameter comprise the following steps:
1) the pumping signal generation module of being located in computer generates pumping signal, and this pumping signal is digital signal, and this digital signal is exported after digital-to-analogue analog-to-digital conversion module is converted to analog signal;
2) power amplifier exports measured device to after the analog signal of digital-to-analogue analog-to-digital conversion module output is amplified;
3) voltage tester fixture is measured the voltage signal at measured device two ends, current sensor measurement flows through the current responsing signal of measured device, the current signal obtaining and voltage signal input digital-to-analogue analog-to-digital conversion module, after being converted to digital signal by digital-to-analogue analog-to-digital conversion module, send into response signal sampling and processing module, again signal is after treatment input to linear dimensions recognition module and nonlinear parameter recognition module, the identification processing of linear dimensions identification model and large-signal Volterra (Volterra) Model Distinguish of nonlinear parameter recognition module through linear parameter identification module are processed, obtain linear dimensions and the nonlinear parameter of loud speaker.
The linear dimensions of loud speaker comprises
r e,
l 0,
l ces ,
r es with
c mes ; The nonlinear parameter number of loud speaker comprises
bl(
x),
k(
x) and
le(
x), wherein:
Bl(
x) =
b 0 +
b 1 x +
b 2 x 2
K(
x) =
k 0 +
k 1 x +
k 2 x 2
L e (
x) =
l 0 +
l 1 x +
l 2 x 2 。
Measured device comprises that moving-coil speaker unit or loud speaker close case system or loud speaker phase inverting box system.
Because loud speaker can be considered nonlinear device when large-signal encourages, use 2 above frequency excitation loud speakers, will produce a plurality of harmonic waves and intermodulation response item, these responses likely overlap in frequency, cause measuring and lost efficacy, therefore pumping signal of the present invention is selected single-frequency or two-frequency signal.
If pumping signal adopts simple signal, be stepping logarithm swept-frequency signal, its form is:
Wherein,
ufor pumping signal amplitude,
w ifor driving frequency,
w i+ 1
generally press
oct=1/3,1/6,1/12,1/24 and other octave standards or choose by logarithmic relationship,
w i+ 1
/
w i =2
oct ;
t i+1 -t i for a certain driving frequency of pumping signal
w i duration.Amplitude does not produce and impacts the mild transition in ground when guaranteeing that two frequencies are switched, and need to consider the continuity of phase place.Therefore need to be according to the termination phase of a upper signal
.
If pumping signal adopts two-frequency signal, its form is:
。
Wherein, the 1st is amplitude
u 1, fixed frequency is
w 0 pumping signal, for enough vibrating diaphragm displacements are provided, be called displacement excitation signal; The 2nd is amplitude
u 1stepping logarithm swept-frequency signal;
u(
t) be step signal.
If pumping signal adopts simple signal, need to measure 2 overtones bands of fundamental frequency and the spectral line at 3 overtones band places, obtain amplitude and the phase place of 2 subharmonic, 3 subharmonic;
If pumping signal adopts two-frequency signal, 2 rank of frequency and 3 rank intermodulation responses centered by need measurement swept-frequency signal.
When flowing through the electric current of measured device and the voltage at two ends thereof when known, at the equivalent oscillating mass of known measured device
m ms prerequisite under, pass through impedance operator
z(
s) formula, identification obtains linear dimensions; By the relational expression of voltage-displacement Volterra kernel function and electric current-displacement Volterra kernel function, adopt nonlinear least square method identification to obtain nonlinear parameter.
Impedance operator
z(
s) be:
The relational expression of voltage-displacement Volterra kernel function is:
The relational expression of voltage-displacement Volterra kernel function is:
A kind of system of using current sensor measurement loudspeaker parameters of the present invention, comprises computer, and computer is connected with digital-to-analogue analog-to-digital conversion module, and digital-to-analogue analog-to-digital conversion module is connected with power amplifier, four line voltage tester fixtures, current sensor.
In computer, be provided with the pumping signal generation module, response signal sampling and processing module, the line that generate pumping signal
Property parameter identification module, nonlinear parameter recognition module and Subscriber Interface Module SIM, pumping signal generation module, response signal sampling and processing module are connected with digital-to-analogue analog-to-digital conversion module, Subscriber Interface Module SIM is connected with pumping signal generation module, linear dimensions recognition module, nonlinear parameter recognition module, and linear dimensions recognition module, nonlinear parameter recognition module and response signal sampling and processing module are connected.
A kind of method of only using current sensor to carry out identification to loud speaker nonlinear parameter of the present invention is not subject to the restriction of environment, cost, can be applicable to product of production line quality testing and speaker system product and detects.
Accompanying drawing explanation
Fig. 1 is for being used the method module map of current sensor measurement loudspeaker parameters.
Fig. 2 is for being used the system and device module map of current sensor measurement loudspeaker parameters.
Fig. 3 is the large-signal electro-mechanical equivalent circuit figure of loud speaker.
Fig. 4 is the large-signal Volterra model block diagram of loud speaker.
Fig. 5 is the time-frequency figure of current responsing signal.
Fig. 6 is the displacement fundamental frequency, 2 times of embodiment tested speaker and 3 subharmonic response amplitudes and by driving voltage, voice coil loudspeaker voice coil current forecasting result comparison diagram.
Fig. 7 is the displacement fundamental frequency, 2 times of embodiment tested speaker and 3 subharmonic response phases and by driving voltage, voice coil loudspeaker voice coil current forecasting result comparison diagram.
Fig. 8 is impedance operator measurement result and the fitting result comparison diagram of embodiment tested speaker.
Fig. 9 is differential equation Numerical Simulation Results and experimental result comparison diagram.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further illustrated.
The method of the use current sensor measurement loudspeaker parameters that as shown in the figure, the present invention proposes comprises the following steps:
1) the pumping signal generation module 1 of being located in computer 7 generates pumping signal, and this pumping signal is digital signal, and this digital signal is exported after digital-to-analogue analog-to-digital conversion module 8 is converted to analog signal;
2) power amplifier 9 exports measured device 6 to after the analog signal of digital-to-analogue analog-to-digital conversion module 8 outputs is amplified;
3) voltage tester fixture 10 is measured the voltage signal at measured device 6 two ends, current sensor 11 is measured the current responsing signal that flows through measured device, the current signal obtaining and voltage signal input digital-to-analogue analog-to-digital conversion module 8, after being converted to digital signal by digital-to-analogue analog-to-digital conversion module 8, send into response signal sampling and processing module, again signal is after treatment input to linear dimensions recognition module 3 and nonlinear parameter recognition module 4, the identification processing of linear dimensions identification model and large-signal Volterra (Volterra) Model Distinguish of nonlinear parameter recognition module 4 through linear parameter identification module 3 are processed, obtain linear dimensions and the nonlinear parameter of loud speaker.
The linear dimensions of loud speaker comprises
r e,
l 0,
l ces ,
r es with
c mes ; The nonlinear parameter number of loud speaker comprises
bl(
x),
k(
x) and
le(
x), wherein:
Bl(
x) =
b 0 +
b 1 x +
b 2 x 2
K(
x) =
k 0 +
k 1 x +
k 2 x 2
L e (
x) =
l 0 +
l 1 x +
l 2 x 2 。
Measured device 6 comprises that moving-coil speaker unit or loud speaker close case system or loud speaker phase inverting box system.
Because loud speaker can be considered nonlinear device when large-signal encourages, use 2 above frequency excitation loud speakers, will produce a plurality of harmonic waves and intermodulation response item, these responses likely overlap in frequency, cause measuring and lost efficacy, therefore pumping signal of the present invention is selected single-frequency or two-frequency signal.
If pumping signal adopts simple signal, be stepping logarithm swept-frequency signal, its form is:
。
Wherein,
ufor pumping signal amplitude,
w ifor driving frequency,
w i+ 1
generally press
oct=1/3,1/6,1/12,1/24 and other octave standards or choose by logarithmic relationship,
w i+ 1
/
w i =2
oct ;
t i+1 -t i for a certain driving frequency of pumping signal
w i duration.Amplitude does not produce and impacts the mild transition in ground when guaranteeing that two frequencies are switched, and need to consider the continuity of phase place.Therefore need to be according to the termination phase of a upper signal
.
If pumping signal adopts two-frequency signal, its form is:
。
Wherein, the 1st is amplitude
u 1, fixed frequency is
w 0 pumping signal, for enough vibrating diaphragm displacements are provided, be called displacement excitation signal; The 2nd is amplitude
u 1stepping logarithm swept-frequency signal;
u(
t) be step signal.
If pumping signal adopts simple signal, need to measure 2 overtones bands of fundamental frequency and the spectral line at 3 overtones band places, obtain amplitude and the phase place of 2 subharmonic, 3 subharmonic;
If pumping signal adopts two-frequency signal, 2 rank of frequency and 3 rank intermodulation responses centered by need measurement swept-frequency signal.
When flowing through the electric current of measured device and the voltage at two ends thereof when known, at the equivalent oscillating mass of known measured device
m ms prerequisite under, pass through impedance operator
z(
s) formula, identification obtains linear dimensions; By the relational expression of voltage-displacement Volterra kernel function and electric current-displacement Volterra kernel function, adopt nonlinear least square method identification to obtain nonlinear parameter.
Impedance operator
z(
s) be:
The relational expression of voltage-displacement Volterra kernel function is:
The relational expression of voltage-displacement Volterra kernel function is:
。
When digital-to-analogue analog-to-digital conversion module 8 exports pumping signal to power amplifier 9, gather electric current and the displacement instantaneous value of loud speaker, and signal is delivered to response signal sampling and processing module 2, response signal sampling and processing module 2 splits the signal collecting by the frequency of pumping signal, and do fast fourier transform, obtain fundamental frequency response corresponding to each driving frequency and harmonic wave or intermodulation response.
Linear dimensions recognition module 3 is set up linear dimensions identification model
Linear dimensions recognition module 3 is based upon on the basis of loud speaker lumped parameter electromechanical analogy equivalent electric circuit, by equivalent electric circuit, sets up the following differential equation:
。
When speaker operation is during in little amplitude state, formula (3) and formula (4) are carried out to Laplace conversion, can be written as
。
Due to vibrating diaphragm displacement
xit is very little,
bl(
x),
le(
x) and
k(
x) can be considered constant, be designated as respectively
b 0,
l 0with
k 0, in formula (5) and formula (6)
dLe(
x)/
dxitem is 0.Therefore can obtain the impedance operator of loud speaker
z(
s) and voltage-displacement linear transfer function
h u1 (
s), they are respectively:
。
The impedance operator measuring is that power amplifier 9 output voltages are than the mould value of the electric current of the loud speaker of flowing through.
Use nonlinear least square fitting, can be in the hope of
r e,
l 0,
k 0/
b 0 2,
r ms/
b 0 2with
m ms/
b 0 2totally 5 values.Due to
m msbe a value that is not subject to environmental change impact, in the situation that error allows, can be made as known quantity.Therefore can obtain
b 0and calculate
k 0with
r ms.
non-linear dimensions recognition module is set up nonlinear parameter identification model
When speaker operation is during at large amplitude state, due to parameter
bl(
x),
le(
x) and
k(
x) along with vibrating diaphragm displacement
xvariation and change, its input with output be no longer linear relationship.Use Volterra Series Solution formula (3) and the equation group that formula (4) forms for this reason, obtain the relation of input voltage and output displacement.According to Volterra series theory, the response of non linear system can be expressed as the form of the convolution of each rank kernel function and pumping signal, and suc as formula (9), its block diagram as shown.
In formula,
u(
t) be input,
h 11 rank kernel function of expression system is linear impulse response,
h 2with
h 32 rank and the 3 rank kernel functions that represent respectively system.
Work as input signal
x(
t)=exp (
s 1 t) time, system linear response expression formula is:
y(
t) =
H 1(s
1)exp(
s 1 t) （13）
Except linear response, in output, also there are 2 above harmonic responses of input signal.
Input signal
x(
t)=
exp(
s 1 t)+
exp(
s 2 t) time, only consider 2 rank response outputs, have
y (
t) =
H 1 (s
1) exp(
s 1 t) +
H 1(s
2) exp(
s 2 t) +
H 2 (s 1,
s 1) exp(2
s 1 t) +
H 2(
s 2,
s 2) exp(2
s 2 t) + 2
H 2(
s 1,
s 2) exp(
s 1 t+s 2 t) （14）
In formula, first two is linear response.3rd, 42 subharmonic distortions that correspondence system.
h 2(
s 1,
s 2) be symmetrical, have
h 2(
s 1,
s 2)=
h 2(
s 2,
s 1), therefore the 5th coefficient is 2, corresponding the intermodulation distortion of system.
Input signal
x(
t)=exp (
s 1 t)
+exp (
s 2 t)
+exp (
s 3 t) time, only consider 3 rank response outputs, have
y(
t) =
y 1(
t) +
y 2(
t) +
y 3(
t)+…… （15）
Wherein,
y 1(
t) be that the response of 1 rank kernel function is linear response.
y 2(
t) with
y 3(
t) be respectively the response of 2,3 rank kernel functions, by harmonic response and intermodulation response, formed.Its concrete form is as follows:
y 1(
t) =
H 1(
s 1) exp(
s 1 t) +
H 1(
s 2) exp(
s 2 t) +
H 1(
s 3) exp(
s 3 t) （16）
y 2(
t) =
H 2(
s 1,
s 1) exp(2
s 1 t)+
H 2(
s 2,
s 2) exp(2
s 2 t) +
H 2(
s 3,
s 3) exp(2
s 3 t) +
2
H 2(
s 1,
s 2)exp(
s 1 t+
s 2 t) + 2
H 2(
s 1,
s 3)exp(
s 1 t+
s 3 t) + 2
H 2(
s 2,
s 3) exp(
s 2 t+
s 3 t) （17）
y 3(
t) =
H 3(
s 1,
s 1,
s 1) exp(3
s 1 t) +
H 3(
s 2,
s 2,
s 2) exp(3
s 2 t) +
H 3(
s 3,
s 3,
s 3) exp(3
s 3 t) +
3
H 3(
s 1,
s 1,
s 2)exp(2
s 1 t+
s 2 t) +3
H 3(
s 1,
s 1,
s 3)exp(2
s 1 t+
s 3 t) + 3
H 3(
s 2,
s 2,
s 1)exp(
s 1 +2
s 2 t) +
3
H 3(
s 2,
s 2,
s 3)exp(2
s 2 t+
s 3 t) +3
H 3(
s 3,
s 3,
s 1)exp(
s 1 +2
s 3 t) + 3
H 3(
s 3,
s 3,
s 2)exp(
s 2 t+2
s 3 t) +
6
H 3(
s 1,
s 2,
s 3) exp(
s 1 t+
s 2 t+
s 3 t) （18）
First 3 of formula (14) is 2 subharmonic responses, and latter 3 is 2 intermodulation response.Similar with it, 3 subharmonic responses referring to
y 3(
t) first 3, its remainder is 3 intermodulation response item.Visible, along with analyzing the increase of exponent number, the quantity of intermodulation response item significantly increases.For the ease of setting forth, in specification, only loud speaker is carried out to 1～3 rank Volterra modeling.
Will
bl(
x),
k(
x) with
l e (
x) approximate representation is the form of 2 rank power series, as follows:
Bl(
x) =
b 0 +
b 1 x +
b 2 x 2 （19）
K(
x) =
k 0 +
k 1 x +
k 2 x 2 （20）
L e (
x) =
l 0 +
l 1 x +
l 2 x 2 （21）
Order input
u=exp (
s 1 t)
+exp (
s 2 t)
+exp (
s 3 t), and displacement is the form suc as formula (12), substitution formula (5) and formula (6), can obtain linear kernel function suc as formula (8) by harmonic wave equilibrium method, and 2,3 rank kernel functions are as follows
Wherein, coefficient
q i , R i as follows:
By above-mentioned derivation, can be found out, if the linear dimensions of known loudspeaker, and the harmonic wave of the displacement of known vibrating diaphragm response or intermodulation response, can use nonlinear least-square fitting process to carry out curve fitting, thereby obtain the power series coefficient of nonlinear parameter
b 1,
k 1,
l 1with
b 2,
k 2,
l 2.
If desired known vibrating diaphragm displacement response, just need to measure by vibrating sensor.For fear of using vibrating sensor easily affected by environment, need to from voice coil loudspeaker voice coil electric current, predict the now displacement of loud speaker.Similar with said method, can establish the form that single-frequency current signal encourages the solution of lower loud speaker, by harmonic wave equilibrium method, obtain electric current linear transfer function, 2 rank and 3 rank Volterra kernel functions.
If flow into the electric current of loudspeaker voice coil
i(t) =
A 1exp(
s 1 t) +
A 2exp(
s 2 t) +
A 3exp(
s 3 t) (24
)
Output is made as
y(t) =
y DC +
y 1(
t) +
y 2(
t) +
y 3(
t) (
25)
By formula (21) and formula (22) substitution formula (6), arrange frequency identical entry, can obtain Volterra kernel function expression formula, as follows
In formula,
h ix1
(
s) be the linear kernel function of loud speaker of current drives,
h ix2
(
s 1,
s 2) and
h ix3
(
s 1,
s 2,
s 3) be respectively 2 rank and 3 rank Volterra kernel functions.
The power amplifier 9 driving for voltage, if ignore the nonlinear distortion impact in circuit, output only comprises the linear response of pumping signal in the voltage at loud speaker two ends.Loud speaker is subject to electromagnetic force driving to start, after vibration, can in voice coil loudspeaker voice coil, generate motional electromotive force
ε=
bl(
x)
v.This electromotive force is closely related with the vibration of membrane of shaking, and in vibrational system, the distortion of displacement response is embodied in motional electromotive force
εin.Change
εmake the curent change in electric loop, therefore comprise the information of this Non-Linear Vibration in electric current.By current sensor, can measure obvious nonlinear distortion, as.Utilize 1～3 rank electric current-displacement Volterra kernel function under current drives to obtain the displacement response of vibrating diaphragm.By 1 rank Volterra kernel function under current drives, can obtain displacement fundamental frequency response.
2 order harmonics responses are:
3 order harmonics responses are:
The item of its acceptance of the bid dotted line underscore is 1～3 rank response item.Response item more than 3 rank is ignored, and arranged by the frequency of response, can obtain the relational expression of current response and displacement response.Suc as formula (32), the displacement response of driving voltage prediction and the displacement response of flowing through the current forecasting of voice coil loudspeaker voice coil are placed on to both members, can obtain an equation group.In equation group, there is not displacement, only occurred voltage
uand current response
i 1~
i 3, these parameters by experiment device measuring obtain.Each kernel function expression formula in equation group is known, and its nonlinear parameter is unknown, can adopt nonlinear least square fitting by nonlinear parameter identification out.
a kind of system of using current sensor measurement loudspeaker parameters of the present invention, comprise computer 7, computer 7 is connected with digital-to-analogue analog-to-digital conversion module 8, and digital-to-analogue analog-to-digital conversion module 8 is connected with power amplifier 9, four line voltage tester fixtures 10, current sensor 11.
In computer 7, be provided with generate pumping signal pumping signal generation module 1, response signal sampling and processing module 2,
Linear dimensions recognition module 3, nonlinear parameter recognition module 4 and Subscriber Interface Module SIM 5, pumping signal generation module 1, response signal sampling and processing module 2 are connected with digital-to-analogue analog-to-digital conversion module 8, Subscriber Interface Module SIM 5 is connected with pumping signal generation module 1, linear dimensions recognition module 3, nonlinear parameter recognition module 4, and linear dimensions recognition module 3, nonlinear parameter recognition module 4 and response signal sampling and processing module 2 are connected.
Subscriber Interface Module SIM 5 provides the functions such as test interface, the judgement of user's input parameter and preservation, measurement result demonstration.
In computer 7, move the software that comprises method of testing of the present invention, controlling digital-to-analogue analog-to-digital conversion module 8, realizing the functions such as calibration and measurement, parameter identification and result demonstration.
Digital-to-analogue analog-to-digital conversion module 8 is realized the mutual conversion of digital signal and analog signal.The pumping signal that pumping signal generation module 1 in computer 7 generates is digital signal, after this module converts, is output as analog signal.
Power amplifier 9 amplifies the analog signal of digital-to-analogue analog-to-digital conversion module 8, exports tested speaker 6 to.In the output loop of power amplifier 9, be connected in series current sensor 11, the voltage at current sensor 11 two ends adopts the four lines measuring method access digital-to-analogue analog-to-digital conversion module 8 by four line voltage tester fixtures.
Now by the order of each module of the present invention, its method of testing is described.
The pumping signal that the embodiment of the present invention is selected is simple signal.Before test, user need to provide the basic parameter of test product to Subscriber Interface Module SIM 5, comprise the voltage amplitude of pumping signal
u, frequency sweep start-stop frequency
f 1,
f 2and frequency sweep frequency step.Such as
u=1V,
f 1=20Hz,
f 2=20kHz, frequency sweep frequency is increased progressively by initial frequency by third-octave relation.
Above-mentioned pumping signal exports power amplifier 9 to by digital-to-analogue analog-to-digital conversion module 8.Power amplifier 9 promotes tested speaker 6 sounding.Digital-to-analogue analog-to-digital conversion module 8 gathers four voltages of line voltage tester fixture 10 and the output of current sensor 11, and stores in computer 6.By calculating, obtain amplitude and the phase place of fundamental frequency response corresponding to each driving frequency, 2 subharmonic and the response of 3 subharmonic, as 6-Fig. 7.
Flow through measured device 6(loud speaker) electric current and the voltage at two ends thereof and to flow through the electric current of loud speaker known, therefore can obtain impedance operator
z(
s), known
m ms prerequisite under identification obtain linear dimensions.Similarly, according to the relational expression of voltage-displacement Volterra kernel function and electric current-displacement Volterra kernel function, adopt nonlinear least square method identification to obtain nonlinear parameter.
In order to verify identification result, above-mentioned parameter was returned in the differential equation of loud speaker by generation.By numerical method, can calculate linear response and the harmonic distortion of loud speaker under another voltage, and itself and measurement result are compared.Can use error
ethe measurement consistency with measurement result that predicts the outcome,
（33）
Wherein
wrepresent weighting function, form is
（34）
Use electric current identification nonlinear parameter, and be respectively 4.9%, 18.8% and 28.1% for the error of predictive displacement linear response, 2 rank responses and the response of 3 rank, a little less than the error 6.2%, 11.6% and 11.9% of using laser.
In embodiment, digital-to-analogue analog-to-digital conversion module 8 is supported 4 passage inputs, 4 passage outputs, 24 of sampling resolutions, and sample rate reaches as high as 192kHz.Power amplifier 9 power outputs can reach 100W, and distortion is less than 0.001%.The range 40mm of four line voltage tester fixtures 10, precision 4mm, the frequency range of measuring displacement is direct current～1000Hz.Current sensor 11 is measuring 4 linear heat generation rate resistance, resistance 0.100 Ω.Tested speaker 6 is the auto loud hailer of 6.5 cun of diameters.
Above embodiment is only in order to illustrate the present invention and unrestricted technical scheme described in the invention; Therefore, although this specification has been described in detail the present invention with reference to each above-mentioned embodiment,, those of ordinary skill in the art should be appreciated that still and can modify or be equal to replacement the present invention; And all do not depart from technical scheme and the improvement thereof of the spirit and scope of invention, it all should be encompassed in the middle of claim scope of the present invention.
Each meaning of parameters of the present invention sees the following form:
Claims (3)
1. use a method for current sensor measurement loudspeaker parameters, it is characterized in that the method comprises the steps:
1) the pumping signal generation module of being located in computer generates pumping signal, and this pumping signal is digital signal, and this digital signal is exported after digital-to-analogue analog-to-digital conversion module is converted to analog signal;
2) power amplifier exports measured device to after the analog signal of digital-to-analogue analog-to-digital conversion module output is amplified;
3) voltage tester fixture is measured the voltage signal at measured device two ends, current sensor measurement flows through the current responsing signal of measured device, the current signal obtaining and voltage signal input digital-to-analogue analog-to-digital conversion module, after being converted to digital signal by digital-to-analogue analog-to-digital conversion module, send into response signal sampling and processing module, again signal is after treatment input to linear dimensions recognition module and nonlinear parameter recognition module, the identification processing of linear dimensions identification model and the large-signal Volterra Model Distinguish of nonlinear parameter recognition module through linear parameter identification module are processed, obtain linear dimensions and the nonlinear parameter of loud speaker,
Described pumping signal is selected single-frequency or two-frequency signal;
If pumping signal adopts simple signal, adopt stepping logarithm swept-frequency signal, its form is:
Wherein,
ufor pumping signal amplitude,
w ifor driving frequency,
w i+ 1
press
oct=1/3,1/6,1/12,1/24 or choose by logarithmic relationship,
w i+ 1
/
w i =2
oct ;
t i+1 -t i for a certain driving frequency of pumping signal
w i duration; Amplitude does not produce and impacts the mild transition in ground when guaranteeing that two frequencies are switched, and need to consider the continuity of phase place; Therefore need to be according to the termination phase of a upper signal
calculate the first phase of each signal
;
If pumping signal adopts two-frequency signal, its form is:
(
)
Wherein, the 1st is amplitude
u 1, fixed frequency is
w 0 pumping signal, for enough vibrating diaphragm displacements are provided, be called displacement excitation signal; The 2nd is amplitude
u 2;
u(
t) be step signal;
If pumping signal adopts simple signal, need to measure 2 overtones bands of fundamental frequency and the spectral line at 3 overtones band places, obtain amplitude and the phase place of 2 subharmonic, 3 subharmonic;
If pumping signal adopts two-frequency signal, 2 rank of frequency and 3 rank intermodulation responses centered by need measurement swept-frequency signal.
2. the method for use current sensor measurement loudspeaker parameters according to claim 1, is characterized in that loud speaker
Linear dimensions comprise
r e,
l 0,
l ces ,
r es with
c mes ; The nonlinear parameter of loud speaker comprises
bl(
x),
k(
x) and
le(
x), wherein:
Bl(
x) =
b 0 +
b 1 x +
b 2 x 2
K(
x) =
k 0 +
k 1 x +
k 2 x 2
L e (
x) =
l 0 +
l 1 x +
l 2 x 2
r e for D.C. resistance,
r es for vibration equivalent resistance,
l 0 l 1 l 2 for the relevant voice coil loudspeaker voice coil inductance of displacement
le(
x) 2 rank block power series coefficient,
c mes for vibration equivalent electric capacity,
l ces for vibration equivalent inductance,
bl(
x) be electromechanical coupling factor,
k(
x) be stiffness.
3. the method for use current sensor measurement loudspeaker parameters according to claim 1, is characterized in that measured device comprises that moving-coil speaker unit or loud speaker close case system or loud speaker phase inverting box system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110083837.3A CN102118678B (en) | 2011-04-02 | 2011-04-02 | Method and system for measuring speaker parameters by using current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110083837.3A CN102118678B (en) | 2011-04-02 | 2011-04-02 | Method and system for measuring speaker parameters by using current sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102118678A CN102118678A (en) | 2011-07-06 |
| CN102118678B true CN102118678B (en) | 2014-07-23 |
Family
ID=44217238
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110083837.3A Expired - Fee Related CN102118678B (en) | 2011-04-02 | 2011-04-02 | Method and system for measuring speaker parameters by using current sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102118678B (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9301072B2 (en) * | 2012-03-05 | 2016-03-29 | Knowles Ipc (M) Sdn. Bhd. | Transducer with motion control |
| CN102970647B (en) * | 2012-11-16 | 2015-04-01 | 嘉善恩益迪电声技术服务有限公司 | Simulating calculation method for nonlinear characteristics in loudspeaker vibration |
| CN103269470B (en) * | 2013-06-06 | 2015-07-15 | 无锡杰夫电声有限公司 | Multi-point excitation source loudspeaker clamp |
| CN103269464B (en) * | 2013-06-06 | 2015-07-15 | 无锡杰夫电声有限公司 | Multipoint excitation source loudspeaker clamp |
| CN106612479A (en) * | 2015-10-23 | 2017-05-03 | 钰太芯微电子科技（上海）有限公司 | Loudspeaker based protective circuit |
| CN105792079A (en) * | 2016-03-28 | 2016-07-20 | 歌尔声学股份有限公司 | Loudspeaker module, loudspeaker system and diaphragm balance adjusting method |
| CN106068007B (en) * | 2016-06-07 | 2019-09-13 | 瑞声科技(新加坡)有限公司 | Nonlinear loudspeaker system identifying method |
| WO2019233416A1 (en) * | 2018-06-05 | 2019-12-12 | Dong Yaobin | Electrostatic loudspeaker, moving-coil loudspeaker, and apparatus for processing audio signal |
| CN109218953A (en) * | 2018-08-13 | 2019-01-15 | 广州市星睿科技有限公司 | One kind being used for sound equipment sound film quality amount detection systems and method |
| CN109218954A (en) * | 2018-08-13 | 2019-01-15 | 广州市华星电器有限公司 | One kind being used for sound equipment sound film quality amount detection systems and method |
| CN110083944B (en) * | 2019-04-28 | 2023-04-07 | 重庆理工大学 | Electromechanical coupling hybrid modeling method for electric drive system |
| CN111916100A (en) * | 2019-05-07 | 2020-11-10 | 北京地平线机器人技术研发有限公司 | Echo cancellation method and apparatus, storage medium, and electronic device |
| CN110502111B (en) * | 2019-08-09 | 2021-02-26 | 瑞声科技(新加坡)有限公司 | Motor signal compensation method, electronic device, and storage medium |
| CN111565353B (en) * | 2020-03-10 | 2021-05-28 | 南京大学 | Speaker nonlinear parameter identification method with self-adaptive multi-step length |
| CN111796793A (en) * | 2020-06-12 | 2020-10-20 | 瑞声科技(新加坡)有限公司 | Speaker system identification method and device, storage medium and communication terminal |
| CN111698633B (en) * | 2020-06-29 | 2021-06-08 | 时东阳 | Method for measuring TS parameters of loudspeaker |
| CN111880092B (en) * | 2020-07-10 | 2023-06-27 | 瑞声新能源发展(常州)有限公司科教城分公司 | Chirp signal Hammerstein model system identification method |
| CN112995882B (en) * | 2021-05-11 | 2021-08-13 | 杭州兆华电子有限公司 | Intelligent equipment audio open loop test method |
| CN113465724A (en) * | 2021-06-22 | 2021-10-01 | 西安艾科特声学科技有限公司 | Secondary sound source with fault detection function for active noise reduction equipment and fault detection method |
| CN114141224B (en) * | 2021-11-30 | 2023-06-09 | 北京百度网讯科技有限公司 | Signal processing method and device, electronic equipment and computer readable medium |
| CN115550829B (en) * | 2022-11-28 | 2023-02-28 | 杭州兆华电子股份有限公司 | Method and system for testing T/S parameters of loudspeaker |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6058195A (en) * | 1998-03-30 | 2000-05-02 | Klippel; Wolfgang J. | Adaptive controller for actuator systems |
| CN1761366A (en) * | 2005-08-18 | 2006-04-19 | 南京大学 | Method for measuring non-linear parameters of speaker unit based on system identification |
| US20070253562A1 (en) * | 2006-04-27 | 2007-11-01 | Kite Thomas D | Method and apparatus for measuring characteristics of an audio system using a tapered chirp |
| CN101442698B (en) * | 2008-09-26 | 2014-04-09 | 嘉兴中科声学科技有限公司 | Method for measuring linear parameter of loudspeaker |
-
2011
- 2011-04-02 CN CN201110083837.3A patent/CN102118678B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN102118678A (en) | 2011-07-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102118678B (en) | Method and system for measuring speaker parameters by using current sensor | |
| CN102158793B (en) | Method utilizing laser sensor to measure speaker parameters and system | |
| CN101600144B (en) | Method and system for obtaining a plurality of parameters of electro-acoustic product by adopting continuous logarithmic swept-frequency signal | |
| CN102742300B (en) | Control of a loudspeaker output | |
| US9578416B2 (en) | Control of a loudspeaker output | |
| CN104837092B (en) | Echo cancel method and assembly for Electroacoustic communications equipment | |
| CN101442698B (en) | Method for measuring linear parameter of loudspeaker | |
| US10123116B2 (en) | Linear and non-linear speaker excursion modeling | |
| CN101411213A (en) | Calibration method and device in an audio system | |
| CN102843633A (en) | Control of loudspeaker output | |
| US9357300B2 (en) | Systems and methods for protecting a speaker | |
| CN101426169B (en) | Time-domain tracking filter quickly detecting acoustic response parameter of sounding body and system | |
| EP2642769A1 (en) | A loudspeaker drive circuit for determining loudspeaker characteristics and/or diagnostics | |
| CN103686530A (en) | Method for processing an audio signal with modeling of the overall response of the electrodynamic loudspeaker | |
| CN106105264A (en) | Integrated self-test for dynamo-electric capacitance type sensor | |
| CN110907827B (en) | Motor transient distortion measuring method and system | |
| EP2456229A1 (en) | Loudspeaker system and control method | |
| CN103414978A (en) | Sound intensity instrument frequency response calibrating device of acoustic coupler method | |
| CN104363554B (en) | A kind of loudspeaker abnormal sound detection method | |
| CN111796792B (en) | Gesture motion judging method and device, electronic equipment and storage medium | |
| US11347912B2 (en) | Prediction method of porous material and the system thereof | |
| CN109655735B (en) | Power amplifier chip evaluation board and power amplifier chip evaluation board system | |
| CN112804626B (en) | Method and system for dynamically controlling amplitude of loudspeaker and mobile terminal | |
| CN103796135A (en) | Dynamic speaker management with echo cancellation | |
| WO2017220816A1 (en) | Method for simulating total harmonic distortion of a loudspeaker |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140723 |