Loudspeaker nonlinear compensation method and apparatus

Patent metadata

Field	Value
Publication number	US-10080085-B2
Application number	US-201715587547-A
Country	US
Kind code	B2
Filing date	May 5, 2017
Priority date	Jun 7, 2016
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

The invention provides a loudspeaker nonlinear compensation method. The method includes steps: obtaining system parameter of the loudspeaker, the No. i time-domain excitation voltage signal and the No. i state vector of the loudspeaker; compensating the No. i time-domain excitation voltage signal according to the system parameter and the No. i state vector and obtain i compensation voltage signal; obtaining the No. i+1 state vector according to the calculation of the system parameter and the No. i compensation voltage signal; outputting the No. i compensation voltage signal and record the quantity of the compensation voltage signal; judging whether the quantity of the compensation voltage signal is equal to the preset number value.

First claim

What is claimed is:

1. A loudspeaker nonlinear compensation method including the following steps of:
S 1 : obtaining system parameters of a loudspeaker, No. i time-domain excitation voltage signal and the No. i state vector of the loudspeaker, among which i is natural number, obtaining system parameter of the loudspeaker including the following steps: measuring the voltage signal and current signal on both ends of the loudspeaker synchronously; utilizing system identification method to obtain the system parameter of the loudspeaker;
S 2 : compensating the No. i time-domain excitation voltage signal according to the system parameter and the No. i state vector, and then obtaining No. i compensation voltage signal;
S 3 : obtaining No. i+1 state vector according to system parameter and the calculation of No. i compensation voltage signal;
S 4 : output the No. i compensation voltage signal and record quantity of the compensation voltage signal;
S 5 : judging whether quantity of the compensation voltage signal is equal to a predetermined value; If so, terminate compensation; if not, command i=i+1, return to execute step S 1 ;
the system parameter including linear parameters and nonlinear parameters; the linear parameters including voice coil DC resistance, voice coil inductance, force factor linear term, stiffness factor linear term and mechanical resistance linear term; the nonlinear parameters including force factor, coefficient of stiffness and mechanical resistance, where the force factor, the coefficient of stiffness and the mechanical resistance are represented respectively are:

Bl
⁡

(
x
)

=

∑

j
=
0

N

⁢

b
j

⁢

x
j

k
t

⁡

(
x
)

=

∑

j
=
0

N

⁢

k
j

⁢

x
j

R
m

⁡

(
v
)

=

∑

j
=
1

N

⁢

r
j

⁢

v
j

,

where, x represents the displacement of vibrating diaphragm of loudspeaker, v represents the velocity of vibrating diaphragm of loudspeaker, Bl(x) represents force factor, kt(x) represents coefficient of stiffness, Rm(v) represents mechanical resistance;
the state vector of the loudspeaker including current, displacement of vibrating diaphragm and velocity of vibrating diaphragm, the state vector being shown as:
x=[x 1 x 2 x 3 ] T =[ixv] T

in step S 3 , the i+1 state vector is obtained through resolving ordinary differential equation according to the system parameter and the No. i compensation voltage signal, the ordinary differential equation of the loudspeaker is:

x
.

=

[

-

R
e

L
e

⁢

x
1

-

Bl
⁡

(

x
2

)

L
e

⁢

x
3

+

u
⁡

(
t
)

L
e

x
3

Bl
⁡

(

x
2

)

m
t

⁢

Assignees

• Aac Technologies Pte Ltd

Inventors

• Hu Yuxiang
• Lu Jing
• Zhang Henglizi

Classifications

• H04R29/001

  for loudspeakers (H04R29/007 takes precedence) · CPC title

• H04R2430/03

  Synergistic effects of band splitting and sub-band processing · CPC title

• H04R29/003

  of the moving-coil type · CPC title

• H04R3/00 Primary

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title

• H03G7/002

  in untuned or low-frequency amplifiers, e.g. audio amplifiers (H03G7/007, H03G7/001, H03G7/008, H03G7/02, H03G7/06 take precedence) · CPC title