close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPH0580784

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH0580784
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
control device for controlling engine noise to be low in the interior of a vehicle.
[0002]
2. Description of the Related Art Heretofore, as a noise control device of this type, for example,
there is one shown in Japanese Patent Laid-Open No. 1-501344. For example, as shown in FIG. 8,
M microphones 1, 1,... Arranged at a predetermined position in a passenger compartment 32 to
be subjected to noise control to detect sound, and a predetermined one in the passenger
compartment 32. The L microphones 2, 2,... Arranged at positions to generate sounds in the
vehicle compartment 32, and the synthetic sound of the noise in the vehicle compartment 32 and
the sound emitted from each speaker 2 is The microphone signals e1 to eM are output from the
microphone 1. The speaker signals y1 to yL outputted to the respective speakers 2 are obtained
by passing signals called reference signals x outputted from the reference signal output device
103 to the digital filters F1 to FL.
[0003]
Reference numeral 15 denotes a speaker signal generation device comprising a CPU for
generating output signals y1 to yL to the speakers 2 by operating the digital filters F1 to FL, and
10-04-2019
1
the adaptive algorithm unit in the speaker signal generation device 15 The parameters of the
digital filters F1 to FL are automatically adjusted so that the sum of squares of the synthesized
speech signals detected by the microphones 1 is minimized by S16. As an algorithm for this
adjustment, the Least Mean Square Method (= LMS) is performed, and this adjustment reduces
the sound detected by each microphone 1 based on the reference signal x from the reference
signal output device 103. , Output signals y1 to yL to the respective speakers 2 are generated.
The reference signal x is a digital filter
[0005]
Input to the adaptive algorithm unit 16 via the
[0007]
This is a model of the transfer characteristic between the L-th speaker 2 and the M-th
microphone 1.
[0008]
In the above-mentioned speaker signal generation device 15, since signal processing is
performed by digital calculation, a microphone comprising an A / D converter 6 in the input
stage of the reference signal x and a linear amplifier in the input stage of the microphone signals
e1 to eM. , And A / D converters 18, 18,..., And speaker amplifiers 20, 20 comprising D / A
converters 19, 19,... And linear amplifiers in the output stages of the speaker signals y1 to yL.
Are provided, and the reference signal x output from the reference signal output device 103 is
input to the speaker signal generation device 15.
Further, microphone signals e1 to eM consisting of analog signals outputted from the respective
microphones 1 are respectively amplified by the microphone amplifier 17 and then digital
converted by the A / D converter 18 and inputted to the speaker signal generating device 15.
Furthermore, the digital signals output from the speaker signal generation device 15 are
respectively converted into speaker signals y1 to yL of analog signals by the D / A converter 19,
then amplified by the speaker amplifier 20 and output to the speakers 2 .
[0009]
10-04-2019
2
The reference signal x is a signal obtained from a vehicle noise source such as engine noise and
running noise, and is highly correlated with the noise. For example, in the case of engine noise, in
particular, noise levels of twice the engine rotation speed (secondary sound) and four times
(fourth sound) are strongly audible, and sine wave signals of these frequencies should be used as
the reference signal x Thus, engine noise that changes according to the operating state of the
engine is controlled. In this case, as shown in the figure, the ignition pulse detector 104 detects
an ignition pulse signal of the on-vehicle engine, shapes the waveform of the signal by the
waveform shaper 105, converts it into a digital signal, and converts it into a sine wave signal by
the reference signal generator 107. To generate.
[0010]
Specifically, in order to obtain a sine wave signal as the reference signal x, in the above
conventional example, after dividing the ignition pulse signal of the engine, tracking by the
tracking filter to obtain the reference signal x or the cycle of the ignition pulse A method is
shown to generate a sinusoidal reference signal x based on this.
[0011]
However, in the above conventional method, a special tracking filter and a counter for measuring
an ignition pulse period are required, the circuit configuration and the arithmetic processing are
complicated, and the time for the arithmetic operation is increased. There was a problem of this.
[0012]
The present invention has been made in view of such various points, and its object is to control
the engine noise by improving the method of generating the sine wave signal as the reference
signal, thereby simplifying the circuit configuration of the reference signal and It is to be able to
generate quickly by arithmetic processing.
[0013]
SUMMARY OF THE INVENTION In order to achieve the above object, the invention according to
claim 1 focuses on the fact that the output signal of the pickup coil in the igniter of the engine
resembles a sawtooth wave signal, and this pickup coil The output signal is linearized to generate
a substantially complete sawtooth wave signal, and based on the sawtooth wave signal, a sine
wave signal as a reference signal is generated.
10-04-2019
3
[0014]
More specifically, in the present invention, a vehicle interior sound detection means for detecting
a sound in the vehicle compartment, a speaker for generating a sound in the vehicle
compartment, and a reference signal output means for outputting a reference signal related to
engine vibration in the vehicle. And noise control device for a vehicle including speaker signal
generation means for generating an output signal to the speaker so that the sound detected by
the vehicle interior sound detection means is reduced based on the reference signal from the
reference signal output means Is a premise.
[0015]
Then, the reference signal output means linearly processes the pickup coil output signal detected
by the pickup coil output detection means for detecting an output signal of the pickup coil in the
igniter of the engine and generates a sawtooth wave signal And a sine wave generating means for
generating a sine wave signal as a reference signal based on the sawtooth wave signal generated
by the linear processing means.
[0016]
According to the above configuration, in the present invention, the output signal of the pickup
coil detected by the pickup coil output detection means is input to the linear processing means
and is linearly processed there, and a sawtooth signal is generated by this linear processing. Ru.
This sawtooth wave signal can be used as information representing an angle that is an integral
multiple of the engine rotation angle, and based on this, a sine wave signal as a reference signal
is generated in the sine wave generation means.
Accordingly, a sine wave signal can be obtained without the need for a conventional tracking
filter or counter, and a reference signal necessary for controlling engine noise can be generated
in a short time by a simple circuit configuration and arithmetic processing.
[0017]
Embodiments of the present invention will be described below with reference to the drawings.
10-04-2019
4
The basic configuration of the noise control system for a vehicle according to this embodiment is
the same as that of the conventional example, and therefore the same parts as those in FIG.
[0018]
That is, this control device controls engine noise, which changes in accordance with the
operating condition of the engine, as noise. As shown in FIG. 2, M microphones 1, 1, ..., L
speakers 2, 2 as shown in FIG. , And a reference signal output device 3 for outputting a reference
signal x related to the vibration of an engine (not shown) in the vehicle, and the microphones 1, 1
based on the reference signal x from the reference signal output device 3 , And so on, and a
speaker signal generating device 15 comprising a CPU that generates output signals y1 to yL to
the speakers 2 so as to reduce the sound detected.
[0019]
6 specifically illustrates the layout of the above-described devices in a car, 31 is a car body, 32 is
a compartment provided at the center of the body 31 and 33 to 36 are doors for opening and
closing the compartment 32. A pair of left and right front seats 37 and 38 are provided on the
front side in the inside 32 and one rear seat 39 is provided on the rear side.
40はステアリングホイールである。
Left and right sides of the headrests 37a and 38a in each of the front seats 37 and 38 (positions
close to the ears of the occupant seated in the front seats 37 and 38), and left and right sides of
the left and right headrests 39a and 39a of the rear seats 39 ... in total (four in the case of M = 4)
are attached to the left and right sides of the occupants seated on the left and right sides of the
occupant), and these microphones 1, 1. Sound is detected near the occupant's ear.
[0020]
Further, five speakers 2 (in the case of L = 5) for generating sound in the passenger compartment
32 are provided at the left and right center of the instrument panel at the front end of the
passenger compartment 32 and the passenger compartment side surfaces of the left and right
front doors 33 and 34, The speakers 2, 2,... Are respectively disposed on the left and right sides
of the package tray portion at the rear end of the passenger compartment 32 and are also used
for audio.
10-04-2019
5
[0021]
The controller 21 for controlling the audio output of the speakers 2, 2,... Is disposed in an
instrument panel in front of the left front seat 38 on the passenger seat side.
In the controller 21, the speaker signal generation device 15, the reference signal output device
3, and the microphone amplifiers 17, 17, ... for amplifying the microphone signals e1 to eM from
the respective microphones 1 and the same signals e1 to eM are digitalized. D / A converters 19
19 converting the A / D converters 18 18 for converting and the reference signal x passed
through the digital filters F 1 to FL into speaker signals y 1 to y L of analog signals Speaker
amplifiers 20, 20,... which amplify y1 to yL and output the amplified signals to the speakers 2 are
incorporated.
[0022]
Further, in the controller 21, an operation switch 22 for switching between the operation of the
noise control system and the audio system by the speaker signal generation device 15 is
disposed in the cabin roof portion.
[0023]
Further, as a feature of the present invention, the reference signal output device 3 includes a
current sensor 4 as pickup coil output detection means for detecting an output signal of the
pickup coil 27 (see FIG. 5) in the igniter 23 of the engine. The sensor 4 is disposed in the engine
room of the vehicle as shown in FIG.
[0024]
The igniter 23 has a known structure, and includes, as shown in FIG. 5, for example, a timing
rotor 24 which is rotationally driven in synchronization with the engine rotation by the output
shaft of the engine. Correspondingly, a plurality of projections 24a, 24a,... Are formed at equal
angular intervals.
An iron core 25 is disposed in the vicinity of the rotor 24 such that the tip thereof is spaced apart
10-04-2019
6
from the projection 24 a of the rotor 24 by a predetermined gap, and the iron core 25 is
connected to the magnet 26 and forms a magnetic field in the iron core 25 by the magnet 26. It
is like that.
When the pickup coil 27 is wound around the outer periphery of the iron core 25 and the
protrusions 24a, 24a,... Come into contact with the tip of the iron core 25 due to the rotation of
the timing rotor 24, an output current as shown in FIG. Is flowing.
[0025]
The tip end portion of each protrusion 24 a and the tip end portion of the iron core 25 in the
timing rotor 24 are each formed in a tapered shape whose tip is sharp at an acute angle, and as
shown by a solid line in FIG. The fall time from the peak of the coil output signal is shortened so
that the signal approaches the sawtooth wave signal (the waveform shown by the phantom line
in FIG. 4 shows the tip of each projection 24 a of the rotor 24 and the iron core The waveform in
the prior art example where all the tip part of 25 is a flat shape is shown).
[0026]
Referring back to FIG. 1 again, the output signal of the current sensor 4 is input to the pickup coil
current sensor amplifier 5, and the signal output from the amplifier 5 is converted into a digital
signal by the A / D converter 6, and then the reference signal is output. It is input to the
generator 7.
The reference signal generator 7 comprises a rectifier 8 for rectifying the output signal of the A /
D converter 6 and a smoothing circuit 9 for smoothing the signal obtained by the rectifier 8, as
shown in detail in FIG. And the circuits 8 and 9 calculate the average effective value of the signal.
The output signal of the smoothing circuit 9 is input to a divider 10, where the signal from the A
/ D converter 6 is divided by its average effective value to adjust the amplitude of the pickup coil
output signal to a constant value. .
[0027]
10-04-2019
7
Further, the signal output from the divider 10 is input to a linearization circuit 11 as a linear
processing means, subjected to linear processing by a map function, and a complete sawtooth
signal is generated by this linear processing.
The output signal of the linearization circuit 11 is input to a sine wave generator 12, which
generates a sine wave signal as the reference signal x based on the sawtooth wave signal. Others
are the same as the conventional example (see FIG. 8).
[0028]
Therefore, in the above embodiment, when the noise control system is operated by the operation
switch 22, the reference signal x of the engine noise output from the reference signal output
device 3 is input to the speaker signal generation device 15. Also, the microphone signals e1 to
eM consisting of analog signals output from the respective microphones 1 are similarly amplified
by the microphone amplifiers 17, 17, ..., respectively, and then digitally converted by the A / D
converters 18, 18, ... The signal is then input to the speaker signal generator 15. Further, digital
signals generated by passing the digital filters F1 to FL in the speaker signal generation device
15 are converted into analog signal speaker signals y1 to yL by the D / A converters 19, 19. The
speaker signals y1 to yL are amplified by the speaker amplifiers 20, 20,...
[0029]
When the reference signal output device 3 generates the reference signal x, first, as shown in
FIG. 3A, the pickup coil output signal detected by the current sensor 4 is digitally converted by
the A / D converter 6 Thereafter, the signal is input to the reference signal generator 7. The
average effective value of the pickup coil output signal is calculated by the rectifier 8 and the
smoothing circuit 9 in the reference signal generator 7, and the output signal is divided by the
average effective value by the divider 10, as shown in FIG. As shown, the amplitude of the output
signal is adjusted to a constant. Furthermore, by linear processing the signal output from the
divider 10 by the linearization circuit 11, a substantially perfect sawtooth wave signal as shown
in FIG. 3C is generated. This sawtooth wave signal is used as information representing an angle
that is an integral multiple of the engine rotation angle, and based on this, a sine wave signal as
the reference signal x is generated by the sine wave generator 12 as shown in FIG. It is
generated.
10-04-2019
8
[0030]
By generating the reference signal x as described above, a sine wave signal can be obtained
without the need for a conventional tracking filter or counter, and the reference signal x
necessary for engine noise control can be obtained by a simple circuit configuration and
arithmetic processing. Can be generated in a short time.
[0031]
In addition, since the tip of each protrusion 24a and the tip of the iron core 25 in the timing
rotor 24 of the igniter 23 are formed in a tapered shape, the fall time from the peak of the
pickup coil output signal is shortened. Can be made closer to a sawtooth signal, so that an
accurate sinusoidal signal can be reliably obtained.
[0032]
In this embodiment, since the speaker 2 in the existing audio apparatus is used, it is only
necessary to add the microphone 1, the reference signal output apparatus 3, the speaker signal
generating apparatus 15 and the like to the audio apparatus, which can be implemented
inexpensively.
[0033]
The configuration of the reference signal generator 7 in the reference signal output device 3 may
be changed as shown in FIG.
That is, the average effective value of the signal is calculated by the rectifier 8 and the smoothing
circuit 9 based on the output signal of the divider 10, and the average effective value is returned
to the divider 10 to adjust the amplitude of the pickup coil output signal to be constant. I am
trying to do it.
Also in this case, the same effect as that of the above embodiment can be obtained.
[0034]
The present invention can also be applied to vehicles other than automobiles.
10-04-2019
9
[0035]
As described above, according to the first aspect of the present invention, the vehicle interior
sound detecting means for detecting the sound in the vehicle compartment and the speaker for
generating the sound in the vehicle compartment are provided as noise sources in the vehicle. In
the vehicle igniter with respect to the vehicle noise control device configured to generate an
output signal to the speaker so that the sound detected by the vehicle interior sound detection
means is reduced based on the reference signal related to the engine vibration. Since the output
signal of the pickup coil is linearly processed to generate a sawtooth wave signal and a sine wave
signal as the reference signal is generated based on the sawtooth wave signal, the reference
necessary for control of engine noise A signal can be generated in a short time by a simple circuit
configuration and arithmetic processing without requiring a tracking filter or a counter.
10-04-2019
10
Документ
Категория
Без категории
Просмотров
0
Размер файла
19 Кб
Теги
description, jph0580784
1/--страниц
Пожаловаться на содержимое документа