JPH03203497A - Active type noise controller - Google Patents

Abstract

PURPOSE:To efficiently execute effective noise control as a whole by selecting the highest noise source in accordance with the operating state of a power generating device out of noises generated from plural noise sources even if the plural noise sources exist and reducing the noise of the selected noise source. CONSTITUTION:The noises of plural noise sources are detected by a crank angle sensor 10, oscillation pickups 12a to 12d and microphones 13a, 13b to be noise generating state detecting means, respective detection signals are individually inputted to adaptive filters prepared in accordance with the number of loud speakers 18a to 18d to be control sound sources as reference signals, filtered by a processor unit 16, added in each control sound source and supplied to respective control sound sources. In parallel with said operation, the driving state of a vehicle or the like is decided, the highest noise is selected based on the decision information and the adaptive filter is controlled based on the detection signal of the noise generating state detecting means corresponding to the selected noise and the detection values of microphones 14a, 14b to be residual noise detecting means so that the noise on the observation position can be minimized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an active noise control device, and in particular, it generates control sound for noise transmitted from a plurality of noise sources to interfere with the noise. The present invention relates to a noise control device that reduces noise and is suitable for reducing noise in vehicle cabins, aircraft cabins, etc.

(Prior Art) Conventionally, as this type of active noise attenuation device, for example, a device described in British Patent Publication No. 2149614 is known. This conventional device is applied to aircraft cabins and similar closed spaces, where a single noise source such as an engine located outside generates sound containing a fundamental frequency f0 and its harmonics f, ~f1. It operates under certain conditions.

Specifically, the above-mentioned conventional device includes a plurality of loudspeakers (secondary sound sources) and microphones installed in a closed space, a frequency detection means for detecting the frequency ".~f" of the noise source, and a plurality of microphones. and a signal processor that supplies a signal having a phase opposite to the detected frequency components f0 to f to a plurality of loudspeakers based on the output signal of the frequency detection means and the detection signal of the frequency detection means. The generated secondary sound and the primary sound transmitted from the noise source interfere to minimize the sound pressure level in the closed space.

(Problem to be Solved by the Invention) However, the above-mentioned conventional device only uses a single noise source (-
Since the structure is configured to reduce noise in a closed space generated from a blowing sound source, for example, when noise is transmitted from multiple noise sources, the noise reduction target related to the frequency detection means may be set to any one of the noise sources. It was not suitable for reducing noise transmitted from multiple noise sources, as it had to be applied in a limited manner.

On the other hand, multiple conventional devices are used for multiple noise sources.

It is also possible to install them in parallel and drive each microphone independently, but in such a case, the equipment would become larger and more complex, and the residual noise at each observation point, that is, each microphone installation position, would be increased. The system is controlled arbitrarily by multiple individual systems, resulting in problems such as significant differences in noise levels between observation points and a deterioration in the control balance of the observation points as a whole.

The present invention was made by focusing on the problems of such conventional devices, and the problem to be solved is that even when there are multiple noise sources, the noise generated from those noise sources can be reduced. The purpose is to select and reduce the most dominant noise source according to the operating state of the power generator at that time, and to perform efficient and effective noise control as a whole.

[Means for Solving the Problems] In order to solve the above problems, in the invention described in claim (1), a control sound is transmitted from a control sound source to an acoustic space where noise is transmitted from a plurality of noise sources having no correlation with each other. The active noise control device is configured to reduce the noise by generating a plurality of noise sources, the plurality of noise generation state detection means for individually detecting signals related to the noise generation states of the plurality of noise sources, and the plurality of noise generation states. adaptive filters are provided for each of the detection signals of the detection means at least as many times as there are control sound sources, and each of the detection signals is individually input; a control sound source drive means for supplying a sound source; a residual noise detection means for detecting residual noise at an observation position in the acoustic space; a driving state determining means for determining a driving state; and a determination by the driving state determining means. noise selection means for selecting the most dominant noise among the noises transmitted from the plurality of noise sources based on the results; a detection signal of the noise generation state detection means corresponding to the noise selected by the noise selection means; and adaptive control means for controlling the adaptive filter so that noise at the observation position is minimized based on the detection value of the residual noise detection means.

Furthermore, in the invention described in claim (2), an active noise source is provided in which a control sound is generated from a control sound source in an acoustic space where noise is transmitted from a plurality of noise sources having no correlation with each other to reduce the noise. In the control device, a plurality of noise generation state detection means for individually detecting signals related to the noise generation state of the plurality of noise sources, an operation state determination means for determining the operation state, and a plurality of noise generation state detection means for determining the operation state, based on the determination result of the operation state determination means. residual noise detection means for detecting residual noise at an observation position in the acoustic space; and adaptive control means for driving the control sound source so that the noise at the observation position is minimized based on the detection value of the residual noise detection means and the selection signal of the noise selection means.

[Operation] In the invention described in claim (1), the noise generation states of the plurality of noise sources are respectively detected by the noise generation state detection means, and each of the detection signals is used as a reference signal to detect the noise generation state of the control sound source for each of the reference signals. They are individually input to adaptive filters equipped according to the number of filters and subjected to filtering processing. The outputs of the plurality of adaptive filters are ba-calculated for each control sound source by the control sound source driving means and supplied to the control sound source, so that the control sound source generates control sound based on the drive command. In parallel with this, the driving state of the vehicle or the like is determined by the driving state determining means, and based on this determination information, the most dominant noise is selected by the noise selecting means. Therefore, the adaptive control means controls the adaptive filter so that the noise at the observation position is minimized based on the detection signal of the noise generation state detection means corresponding to the noise selected by the noise selection means and the detection value of the residual noise detection means. do. Thereby, even if there are multiple noise sources, the dominant noise at the observation position is accurately reduced by interference with the control sound.

Further, in the invention described in claim (2), signals regarding the noise generation states of the plurality of noise sources are individually detected by the plurality of noise generation state detection means, and the driving state of the vehicle etc. is determined by the driving state determination means. . Then, based on the determination result of the driving state determining means, the noise selecting means selects a detection signal corresponding to the most dominant noise from among the detection signals of the plurality of noise generation state detecting means. Therefore, the adaptive control means drives the control sound source so that the noise at the observation position is minimized based on the detection value of the residual noise detection means and the detection signal of the noise selection means. Therefore, by selecting the dominant noise in advance and subjecting it to signal processing, a simplified configuration can be achieved.

(Embodiment) An embodiment of the present invention will be described below with reference to Figs. 1 to 3. In this embodiment, a vehicle is used as a power generating device, and the present invention is implemented in this vehicle.

In Fig. 1, 2a to 2d are the wheels, 4 is the engine, 6 is the closed space inside the vehicle, 8f and 8r are the front and rear seats inside the vehicle 6, and 9 is the seat mounted on the vehicle. An active noise control device is shown.

The active noise control device 9 includes a crank angle sensor 10 as a noise generation state detection means. Vibration pink up 12a~1
2d, and a microphone 13a.

13b, and a microphone 14 as a residual noise detection means.
a to 14h, a vehicle speed sensor 15 for detecting vehicle speed, a processor unit 16 for signal processing, and loudspeakers 18a to 18d as control sound sources.

This will be explained in detail below. The engine 4 is equipped with a crank angle sensor 10 that outputs a crank angle signal X according to engine rotation.

Further, at predetermined positions of the suspension members that suspend the wheels 2a to 2d, road noise signals X2 to X, which are electric signals corresponding to vibrations of the suspension due to unevenness of the road, are provided.
Vibration pickups 12a to 12d are provided for outputting. Furthermore, microphones 13a and 13b are provided on both side door mirrors to detect wind noise as sound pressure signals X, X, which are electrical signals. Furthermore, when a passenger sits on the seats 8f and 8r in the vehicle compartment 6,
A total of 8 microphones 14a for each ear position of each passenger
~14h is attached, microphones 14a-14h
Each detects noise signals te1 to e, which are electrical signals corresponding to the sound pressure at the ear position. In addition, vehicle speed sensor 1
5 detects a signal V corresponding to the vehicle speed.

And crank angle sensor 10. Vibration pickup 12
a to 12d, microphones 13a, 13b, 14a to
14h and the output end of the vehicle speed sensor 15 are individually connected to a processor unit 16 installed at a predetermined position on the vehicle body, and each detection signal is input to the processor unit 16.

Further, the output side of the processor unit 16 is individually connected to a total of four loudspeakers 18a to 18d. Two loudspeakers 18a to 18d are arranged on each side of the vehicle body, facing the front and rear seats 8f to 8r.

The processor unit 16, as shown in FIG.
! ~X, and sound pressure signal X6+X? a first processing unit 19A that processes the loudspeakers 18a to 18d to drive the loudspeakers 18a to 18d, input crank angle signals X++, road noise signals X2 to Xs, sound pressure signals xb, x, noise signals el''
It has a second processing section 19B that controls processing by the first processing section 19A based on e8 and the vehicle speed signal ■.

The first processing unit 19A includes an A/D converter 2 for A/D conversion.
an adaptive filter 22A that performs 0A to 20G1 convolution processing;
~22Du (u=1 to 7), D/A that performs D/A conversion
Converters 24Au to 24Du (u=1 to 7) and an adder 26A for signal addition.

~26D, (u=1 to 6). To explain this in detail, crank angle signal xI + road noise signal X2. . . , Xs and the sound pressure signal are respectively input to the A/D converters 20A to 20G on the input side, and the A/D converter 2
The output side of 0A to 20G is divided into four parts for each signal system, and adaptive filters 22A1 to 22Du (u
= 1 to 7) individually. Each adaptive filter 22A1-2
The output side of 2Du (u-1 to 7) is connected to an adder 26A via D/A converters 24Au to 24Du (u=1 to 7), respectively.

~26D, (u=1 to 6). At this time, D
Of the outputs of the /A converters 24Au to 24Du (u=1 to 7), the first conversion outputs for each signal system are connected to the adder 26.
A,,26A2.26A,,26A,,26As,2
6A6, and the summed output is delivered to the first loudspeaker 18a. Similarly, the second to fourth conversion outputs are connected to each other by adders 26B1 to 26B1.
26B.

26G, ~26C, , 26D, ~26D, are added together by loudspeakers 18b, 18c, 18d.
respectively.

Here, instead of using the D/A converters 24Au to 24Du, the adders 26Au to 26Du are made digital,
A subsequent D/A converter may be provided for each loudspeaker.

The second processing unit 19B also processes the input noise signal el.
xe, A/D converters 28A to 28H, A/D converter 29 that A/D converts the vehicle speed signal
a digital filter 30 which inputs the conversion outputs of the /D converters 28A to 28H and calculates a filtered reference value rLmk, which will be described later; the output r, □ of this filter 30; and the A/D converters 20A to 20G The microprocessor 31 updates the coefficients of the adaptive filters 22A and 22Du (u=1 to 7) by performing necessary calculations to be described later using the conversion output of the adaptive filter 29.

Among these, the digital filter 30 manually inputs 7 to each reference signal X1 to filtered reference signals r, □ (described later (4) , see equation (5)). In this embodiment, the microphone sensor 31 is equipped with a microcomputer, and performs the processing shown in FIG. 3 to determine the driving state of the vehicle, and uses equation (5) described later to determine whether the vehicle belongs to the steepest descent method. A coefficient update calculation based on the LMS algorithm is performed, and a control signal according to the calculation result is applied to the adaptive filters 22A, 22D, (u
=1 to 7). Therefore, the adaptive filters 22Au to 22Du (u=1 to 7) that receive the control signal change their coefficients in accordance with the calculated values of the microprocessor 31.

Here, the control principle according to the present invention will be explained.

Now, the noise signal detected by the first microphone is
, (n) , control sound (cancellation sound) from the loudspeaker
The noise signal detected by the first microphone in the absence of is ept(n), and the jth (j= o, 1, 2.-・=,
IC-1) coefficient is C3□, the second reference signal X, M(n), the kth reference signal xk(n
) of the adaptive filter that drives the mth loudspeaker (i=o, 1.2..., lx
If the coefficient of 1) is W1□, e L (n) −e pl (n) 10(1) holds true. Here, all terms with (n) are sample values at sampling time n, L is the number of residual noise detection microphones (8 in this example), and M is the number of loudspeakers (8). In this example, 4), K is the number of manual channels from the crank angle sensor, vibration pickup, and wind noise detection microphone (7 in this example);
Ic is the number of taps (filter order) of the transfer function C0 expressed by the FIR digital filter, and Ik is the number of taps of the adaptive filter WMk (which may change depending on k).

In the above equation (1), “Σ WMk, x k(n-3
-i)) The term 1(-ysk) is the adaptive filter Wff
It represents the output when signal xk is input to ik, and is expressed as "(Σ
Σ w, kiXm (n-j-i) l J (=y
The term *) represents the sum of the signals input to the m-th speaker, and is expressed as “ICLllj(Σ Σ 1Lkl −Xl
, (n-j-i)) The term J indicates that the signal energy inputted to the m-th speaker is output from the speaker as acoustic energy, and reaches the second microphone via the transfer function CLM in the vehicle interior 6. In addition, ``ΣΣ C1□ ・ (Σ Σ wMki HXk
The entire right side of (n-j-x) l J represents the sum of the two-blow sounds that reach the first microphone, since the signals that reach the first microphone are added up for all speakers.

Next, the evaluation function (variable to be minimized) Je is
ΣTL(e+(n))”
,,, (2). Here, γ is a weighting coefficient for each microphone 14, and by increasing or decreasing this coefficient γ, it is possible to change the importance of the noise level at the microphone position.

In order to find the filter coefficient Wo that minimizes the evaluation function Je, this embodiment employs the LMS algorithm. In other words, the evaluation function Je is defined as each filter coefficient Wmk.

The filter coefficient W,%, is updated with the value partially differentiated with respect to the filter coefficient W,%.

Therefore, from equation (2), ... (3) becomes, but from (1)2... (4), so the right side of this equation (4) is r, □(n-i)
Then, the filter coefficient rewriting formula can be obtained from the following formula (5).

Waitt(n+1)=W+ai+1(n)+(
5) Here, α is a convergence coefficient, and is involved in the speed at which the filter optimally converges and the stability at that time. Although the convergence coefficient α is treated as a single constant in this example, it is also possible to use a different convergence coefficient (α□, ) for each filter coefficient, or to use the same weighting coefficient 7'L. It can also be calculated as a coefficient (α,) taken into .

In the above configuration, A, /D converters 20A to 20G,
28A to 28H, a digital filter 30, and a microprocessor 31 constitute adaptive control means, and D/A converters 24A, to 24D, (u=1 to 7) and an adder 26A.
u to 26Du (u=1""6) constitute a control sound source driving means.

Next, the operation of this embodiment will be explained.

First, the microprocessor 31 executes the
The process shown in FIG. 3, which is executed as a timer interrupt process (0 m5ec), will be explained.

In step ■ in the figure, the microprocessor 31
Input the vehicle speed signal ■ inputted via the D converter 29,
Remember that value. Next, the process moves to step (2), and the rate of change 9 of the vehicle speed (2) is calculated based on the read value in step (2) related to the current interrupt processing and the read value in step (2) related to the interrupt processing a predetermined number of times ago. Next, proceed to step (2), and calculate l> for the calculated value in step (2). (
. is a predetermined dark value that can discriminate a sudden acceleration state. This judgment is to detect a sudden acceleration state, and “N
In the case of "O", it is assumed that there is a sudden acceleration state, and in order to give priority to engine noise control in this sudden acceleration state, the process moves to step (3). In step (2), a command is issued to give priority to engine noise control. Incidentally, in step (2), the engine rotational speed may be read instead of the vehicle speed (2).

On the other hand, if rYEsJ is determined in step (2), it is determined that the acceleration state is not rapid and the process proceeds to step (2). This judgment indicates that the vehicle speed ■ read in step ■ is V>V. (■
. is a predetermined dark value that can distinguish between high speed and low speed.
to move to.

In step (■), a command is issued to give priority to wind noise control.

Furthermore, in the case of rNOJ in step (2), it is assumed that the driving condition is neither rapid acceleration nor high-speed driving, so step (2)
and issues a command to prioritize road noise control.

In this embodiment, vehicle speed sensor 15. The A/D converter 29 and the processing of steps 1 to 3 in FIG.

Next, the overall operation will be explained.

When the vehicle runs, rotational vibrations of the engine 4 are transmitted to the passenger compartment 6 through the vehicle body, and remain in the passenger compartment 6 as muffled noise. The engine rotation state at this time is the crank angle sensor 1.
0, and a crank angle signal Xt corresponding to the rotational speed of the engine 4 is output to the processor unit 16. Additionally, while the vehicle is running, the suspension members vibrate when the road surface is uneven. This results in
Such a vibration state is detected by the vibration pickups 12a-12d, and road noise signals x2-X corresponding to the vibration input from the road surface are output to the processor unit 16. Also, the microphones 13a and 13b send sound pressure signals X6+X? corresponding to wind noise near the door mirror. is output to the processor unit 16. Furthermore, the vehicle speed sensor 15 sends a signal (■) corresponding to the vehicle speed to the processor unit 16.
Output to.

Then, within the processor unit 16, the detection signal x
l~x, are converted into digital quantities by A/D converters 20A~20G, respectively, and then adaptive filters 22A,~
22D, (u=1 to 5) and the microprocessor 31. Further, the vehicle speed signal V is similarly supplied to the microprocessor 31 via the A/D converter 29.

Further, the microphones 14a to 14h detect the sound remaining at their installation positions (observation positions), and similarly output corresponding noise signals e, to e to the processor unit 16. And within the processor unit 16,
The noise signals e1 to e8 are converted into digital quantities by the A/D converters 28a to 28h, and then supplied to the digital filter 30, respectively.

The digital filter 30 converts the value of the input signal into a filtered reference signal rla based on equation (4) above.
k to the microprocessor 31. The microprocessor 31 uses each input value to perform calculations to update the filter coefficients of the adaptive filter that is inputting the reference signal for which the priority command is issued at that time, based on equation (5) above, and Do not update filter coefficients. That is, for those to be updated, the filter coefficient W at the current sampling time n. , (n) are subjected to an evaluation function, that is, a noise signal e corresponding to the residual sound pressure from each microphone 14a to 14h, and a filter coefficient in the direction that minimizes the sum of the squares of (n) is applied to each filter, and the sampling time(
filter coefficient WMki to be set at n+1)
(n+1) is obtained. Then, the microprocessor 31 individually outputs a control signal according to the calculated value W-bi (n+1) to the adaptive filter. Therefore, the filter coefficient of each applicable adaptive filter is updated to the newly calculated filter coefficient W m k i at sampling time (n+1).

Specifically, when engine noise priority control in a rapid acceleration state is commanded in the process shown in FIG. The filter will be updated at an appropriate timing that will not cause any problems, and no other filters will be updated. In addition, when wind noise priority control at high speed is commanded in the process shown in FIG. 3, the eight adaptive filters 22A6 to
The coefficients of only 22Db, 22Ar to 22D7 are updated as appropriate. Furthermore, when road noise priority control is similarly instructed, 16 adaptive filters 22A2 to 22 Dz 22 A3 related to road noise signals X2 to X
~22D3 22A4~22D, 22A, ~22D
, only the coefficients are updated. Any of the above update controls is repeated at predetermined timings so as to minimize the evaluation function Je.

On the other hand, adaptive filters 22Au to 22Du (u=1 to 7
), a convolution operation is performed between the input signals x1 to X and the coefficient W m k i using the filter coefficients set at that time, and an output yffik(n) is obtained. These adaptive filters 22A, ~22D,.

(u=1 to 7) are output from adders 26Au to 24Du.
(u=1 to 6), the output signal y for each speaker drive system. (n) are added, the summation y□(n) is calculated, and the summation signals y, (n) are output to the first to fourth speakers 18a to 18d, respectively.

As a result, each speaker 18a to 18d receives the input signal y
, (n) generates a control sound (two-blow sound). In other words, the control sound with a phase that cancels out the residual noise at the eight observation points (microphone installation positions) is transmitted to the speaker 18a.
~18d, and this control sound propagates through the vehicle interior space corresponding to the previously estimated transfer function C1 based on the directivity of the speaker.

Therefore, in the rapid acceleration state in this embodiment, the engine noise that increases due to a sudden change in the engine driving situation becomes the dominant noise in the vehicle interior 6; For example, the speakers 18a-18d generate control sounds that offset the engine, thereby canceling out the dominant noise. Furthermore, in high-speed driving conditions, increasing wind noise becomes dominant, but this wind noise is reliably reduced by the control sound. Furthermore, road noise, which is dominant in situations other than sudden acceleration and high-speed driving, is reduced.

In this way, at the observation points of the microphones 14a to 14h and their surroundings, depending on the driving conditions of the vehicle, the most dominant noise inside the vehicle at that time is accurately suppressed, reducing the noise that can be heard by the occupants. There is. This eliminates the need for the microprocessor 31 to update the coefficients of all 28 adaptive filters 22Au to 22Du (u=1 to 7) at each sampling time, and in this embodiment, the maximum 16 filters that have been given priority All you need to do is update the coefficients. (-Therefore, there is an advantage that the calculation load on the microprocessor 31 can be reduced, high-speed calculation is not necessarily required, and the cost is low.

Next, another embodiment of the present invention II is shown in FIG. In this figure, the same reference numerals are used for the same components as in FIGS. 1 to 3, and the explanation thereof will be omitted.

The embodiment shown in FIG. 4 was also implemented for a vehicle in the same way as the previous embodiment, and included a crank angle sensor 10, vibration pickups 12a to 12d, and a wind noise microphone 13.
Each detection signal Xi to X of
has been entered.

This selection circuit 50 receives the selection signal SL from the microprocessor 31, and selects a reference signal x, (c=1.2...) selected from among the detection signals X+''-'X7.
Four adaptive filters 54a through A/D converter 52
I am trying to do it manually on 54d. The microprocessor 31 also performs the processing shown in FIG. 3 to output a selection signal SL depending on which sensor's detection signals X1 to x7 are to be selected with priority. In addition, in the figure, 56a to 56d are D/A converters, and 58a to 58d.
is a loudspeaker, and the other embodiments are the same as those described above.

Therefore, in the embodiment according to the configuration shown in FIG. 4, in addition to the same effect as the embodiment described above, the detected sensor signal Since the adaptive signal processing is performed in a state selected in advance according to the degree of transmission, the number of adaptive filters and each circuit on the input/output side thereof can be significantly reduced, which has the advantage of simplifying the configuration. Furthermore, unlike the embodiments described above, no control sound is generated from an adaptive filter that does not update coefficients, so there is an advantage that noise reduction can be carried out with higher precision.

In addition, in the above embodiment, the case where a plurality of loudspeakers as a control sound source and a plurality of microphones as a residual noise detection means are provided, but the active noise control device of the present invention is not necessarily limited to this. ,for example,
There may be one loudspeaker.

Further, the active noise control device of the present invention is not limited to a device applied to a vehicle cabin as in the above-mentioned embodiments, but may be a device applied to an aircraft cabin, for example, or may be a device applied to an aircraft cabin. The device may be configured to reduce indoor noise caused by the rotation of the outdoor air conditioning unit. On the other hand, in the above-mentioned embodiment, a case was explained in which multiple noise sources were located outside a kind of closed space called the passenger compartment.
The present invention can also be applied when the noise source is installed inside such a closed space.

Furthermore, in the embodiment described above, the detection contents of the plurality of noise generation state detection means include a muffled sound caused by engine vibration, a crank angle signal correlated with exhaust noise, a pickup signal of suspension vibration correlated with road noise, Although the present invention is not limited to the configuration described above, the present invention is not limited to the configuration described above. For example, the present invention is not limited to the configuration using microphone signals correlated with It also incorporates pulse signals corresponding to the rotation of the output shaft of the transmission for measuring vehicle speed (signals correlated with noise caused by the meshing of the transmission and differential gears). It may be a channel or a combination of any of these.

Furthermore, the algorithm related to the filter coefficient update of the present invention is based on the time domain L
The algorithm is not limited to the M S (Least Mean 5 square) algorithm, and may be, for example, a frequency domain LMS algorithm.

[Effect of the invention] As explained above, according to the invention described in claim (1),
While signals related to the noise generation status of multiple noise sources are individually detected, the operating status of the power generator is determined, and based on the determination results, the most dominant noise is selected from among the noise caused by multiple noise sources. The adaptive filter performs adaptive signal processing based on the detection signal of the noise generation state detection means corresponding to the selected noise and the detection value of the residual noise detection means. Even if noise is present, it is possible to prioritize and eliminate the noise that is considered to be occurring most dominantly in the acoustic space at the time of control, thereby effectively eliminating noise in the acoustic space such as the passenger compartment. The effect is that the reduction can be carried out effectively.

Further, according to the invention described in claim (2), after individually detecting the signals regarding the noise generation states of the plurality of noise sources, the plurality of noise generation state detection signals are generated based on the determination result of the operating state of the power generator. The detection signal corresponding to the most dominant noise source is selected from among them, and adaptive signal processing is performed based on the selected detection signal and the residual noise detection signal.
In addition to obtaining the same effect as the effect according to the invention described in claim (1), there is an effect that the configuration of filters and the like related to adaptive signal processing can be kept to the minimum necessary and the configuration can be simplified.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is a partially omitted block diagram of the processor unit in the embodiment of FIG. 1, and FIG. FIG. 4 is a block diagram showing a partial configuration of a processor unit according to another embodiment of the present invention. 9 is an active noise control device, 10 is a crank angle sensor, 1
2a to 12d are vibration pickups, 13a and 13b are microphones, 14a to 14h are microphones, 16 is a processor unit, 18a to 18d 58a to 5
8d is loud speaker, 20A~20G, 28A~2
8H, 2952 is an A/D converter, 22A, ~22D
, (u=1 to 7), 54a to 54d are adaptive filters 24A. ~24D, (u=1~7), 56a~56d are D/A converters, 26Au~26D, (u=1~6) are adders, 3
0 is a digital filter, 31 is a microprocessor,
50 is a selection circuit.

Claims (2)

[Claims] (1) In an active noise control device that reduces noise by generating control sound from a control sound source in an acoustic space where noise is transmitted from a plurality of noise sources that have no correlation with each other, the plurality of noise sources have no correlation with each other. a plurality of noise generation state detection means for individually detecting signals related to the noise generation state of the noise sources; and at least as many noise generation state detection means as there are control sound sources for each of the detection signals of the plurality of noise generation state detection means; and a control sound source driving means that adds the respective outputs of the plurality of adaptive filters for each of the control sound sources and supplies the control sound source to the control sound source. a residual noise detection means for detecting the operating state, an operating state determining means for determining the operating state, and selecting the most dominant noise among the noises transmitted from the plurality of noise sources based on the determination result of the operating state determining means. a noise selection means that selects the noise, and the adaptation so that the noise at the observation position is minimized based on the detection signal of the noise generation state detection means corresponding to the noise selected by the noise selection means and the detection value of the residual noise detection means. An active noise control device comprising: adaptive control means for controlling a filter. (2) In an active noise control device that reduces noise by generating control sound from a control sound source in an acoustic space where noise is transmitted from a plurality of noise sources that have no correlation with each other, the plurality of noise sources have no correlation with each other. a plurality of noise generation state detection means for individually detecting signals related to the noise generation state of the source; an operation state determination means for determining the operating state; and a plurality of noise generation state detection means based on the determination result of the operation state determination means. a noise selection means for selecting a detection signal corresponding to the most dominant noise from among the detection signals; a residual noise detection means for detecting residual noise at an observation position in the acoustic space; and detection by the residual noise detection means. 1. An active noise control device comprising: adaptive control means for driving the control sound source so that noise at the observation position is minimized based on the value and the selection signal of the noise selection means.