JPH0798592A - Active vibration control device and its manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a preferable vibration eliminating performance corresponding to a transfer characteristic of vibration covering a vibration source to a vibration eliminating position using an adaptable filter having low resolution and a low cost by restricting a reference signal to the prescribed frequency region being preferable for processing by an adaptable filter. CONSTITUTION:This device is a signal input system transmitted from a detecting microphone to an adaptable filter 22. That is, a fixed filter 24 consisting of analog filter in which the prescribed signal waveform is written is connected in series to the adaptable filter 22 between an amplifier and an A/D converter 21 in the stream side of the adaptable filter 22. A signal waveform of the prescribed frequency region different form a reference signal previously processed by the adaptable filter, that is, a signal waveform of the prescribed frequency which cannot be written in the adaptable filter 22 is written in this fixed filter 24, and this fixed filter 24 restricts the reference signal processed by the adaptable filter 22 so as to be within the prescribed frequency region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration control device for generating an anti-vibration having a phase opposite to that of a vibration from a vibration source from a vibrating means to eliminate the vibration at a predetermined vibration elimination position. The manufacturing method is related. In the present invention, the vibration includes not only pure vibration but also noise, the vibration source includes a noise source, and the vibrating means includes a speaker.

[0002]

2. Description of the Related Art The basic structure of an active vibration control system of this type will be explained. For example, noise is generated from a noise source in a space, and noise at a predetermined position (noise cancellation position) will be erased. In such a case, the noise is detected by a detection microphone in the vicinity of the noise source, and the analog noise signal (reference signal) is converted into a digital value, which is then input to an adaptive filter composed of a digital filter. In this adaptive filter, the reference signal from the detection microphone is processed by gain adjustment and phase adjustment to generate an anti-noise signal having the same amplitude as that of the noise signal, but output to the speaker. And
The anti-noise emitted from the speaker and the original noise from the noise source cancel each other out at the noise elimination position, thereby eliminating the noise at the noise elimination position.

A monitor microphone for observing an error sound that could not be silenced at the noise erasing position is arranged at the noise erasing position, and an error sound at the noise erasing position is generated based on a monitor signal from the monitor microphone. LMS (Least Mean Square Meth
The filter coefficient of the adaptive filter is sequentially updated and optimized by the od (= least squares method) algorithm.

Further, in particular, in the case of eliminating the noise (the muffled sound) from the vehicle-mounted engine in the passenger compartment of the vehicle, attention is paid to the fact that the engine noise is generated in association with the ignition cycle, and the engine noise is detected. Instead of detecting with, the ignition signal is input and a reference signal is generated based on it, and an inversion signal having the opposite phase and the same amplitude to this reference signal is processed by an adaptive filter,
This reversal sound is generated from the speaker inside the vehicle.

In the case of eliminating the noise in the vehicle interior in this way, when the environment in the vehicle interior changes such as the temperature, the seating condition of the occupant, the presence / absence of opening / closing of the window, the noise source and the speaker produce noise. The transfer characteristic of sound up to the erase position (monitor microphone) changes. Therefore, in the past, the applicant of the present application connected a plurality of filters in which predetermined waveforms respectively corresponding to changes in the environment were described in advance to the input side to the adaptive filter, and switched the adaptive filters according to the changes in the environment, By correcting the reference signal input to
It has been proposed that the amount of calculation in the adaptive filter is reduced, the filter is optimized in a short time so that a silencing effect can be obtained, and the response of noise control and the control accuracy are improved (Japanese Patent Laid-Open No. H10 (1999) -135242). (See Japanese Patent Publication No. 5-4541).

[0006]

By the way, for example, when the noise of a blower in a vehicle air conditioner is silenced,
Unlike the engine noise, which has a component that is an integral multiple of the engine rotation frequency, is a wideband random sound that does not have a periodic component. A blower noise is detected by a detection microphone to generate a reference signal, and this reference signal is processed by modeling the sound transmission characteristics from the noise source to the noise elimination position in the signal transfer system from the detection microphone to the speaker and then from the speaker. It is necessary to generate anti-noise.

However, in that case, there are the following two problems. That is, when the present inventor measured the acoustic characteristics in the vehicle interior, noise cancellation from the noise source or speaker due to, for example, the size or shape of the vehicle interior, the position or structure of the seat, the position or structure of the door or window, etc. Position (monitor microphone)
It was found that the sound was absorbed in a predetermined frequency range up to, and there was a singular point peculiar to the passenger compartment in the sound transmission characteristic. Then, in the frequency region that is the singular point, it becomes impossible to describe the signal waveform in the adaptive filter, so that the noise rather increases with the operation of the adaptive filter.

In order to improve the silencing performance in the frequency region of this singular point, it can be solved by increasing the resolution of the adaptive filter consisting of a digital filter, but this causes an increase in the amount of calculation and an expensive adaptive filter. Takes
Increasing costs is inevitable.

As a second problem, when the entire random sound is to be erased by a digital system, fluctuations in acoustic characteristics may occur, for example, a frequency range that is not so uncomfortable for an occupant or an external factor. Although there are few stationary frequency regions, they are collectively processed, so that the amount of processing calculation of the system becomes enormous, and a large controller is required, resulting in high cost.

The present invention has been made in view of the above points, and an object thereof is to improve the structure of a control system.
An inexpensive adaptive filter with low resolution is used to reduce the cost of the vibration control device and to obtain suitable vibration elimination performance corresponding to the transmission characteristics of the vibration from the vibration source to the vibration elimination position. .

[0011]

In order to achieve the above-mentioned object, in the invention of claim 1, the reference signal processed by the adaptive filter is set to a predetermined frequency region suitable for being processed by the adaptive filter. I decided to limit it.

That is, according to the present invention, the vibration detecting means for detecting the vibration of the vibration source and outputting the reference signal,
An adaptive filter that processes the reference signal from the vibration detection means and outputs an anti-vibration signal having the same amplitude as that of the vibration signal, and an excitation that generates an anti-vibration by receiving the anti-vibration signal from the adaptive filter. Means for monitoring the error vibration at the vibration erasing position, and the above-mentioned adaptation so that the error vibration at the vibration erasing position is reduced based on the monitor signal from the monitor means. An active vibration control device provided with a control means for controlling the filter is a prerequisite.

Further, the transfer system of the reference signal transmitted from the vibration detecting means to the adaptive filter is provided with a limiting means for limiting the reference signal processed by the adaptive filter to a predetermined frequency range.

According to a second aspect of the present invention, the limiting means is a filter that passes only the signal in the predetermined frequency region of the reference signal.

In the invention of claim 3, the limiting means is a fixed filter in which a signal waveform in a predetermined frequency region different from the frequency region of the reference signal processed by the adaptive filter is described in advance.

According to the fourth aspect of the present invention, the fixed filter describes a signal waveform in a predetermined frequency region which the adaptive filter cannot describe.

According to a fifth aspect of the present invention, in the active vibration control device based on the same premise as the first aspect of the present invention, a waveform signal in a predetermined frequency region in which the adaptive filter cannot describe is described upstream of the adaptive filter. A fixed filter is placed in series with the adaptive filter.

According to a sixth aspect of the invention, in the active vibration control device based on the same premise as the first aspect of the invention, a signal waveform in a predetermined frequency region different from the frequency region of the reference signal processed by the adaptive filter is described in advance. The fixed filter is provided in parallel with the adaptive filter, and the frequency band of the signal waveform described by the fixed filter is different from the frequency band of the signal waveform described by the adaptive filter.

According to the invention of claim 7, the fixed filter is an analog filter.

According to an eighth aspect of the present invention, information detecting means for detecting that the vibration transfer characteristic from the vibration source to the vibration elimination position has changed from the vibration transfer characteristic corresponding to the signal waveform described in the fixed filter, And a prohibiting means for prohibiting the operation of the fixed filter when the change of the vibration transmission characteristic is detected by the information detecting means.

In the ninth aspect of the present invention, the fixed filter is provided with a plurality of signal waveforms corresponding to the vibration transfer characteristics from the vibration source to the vibration elimination position and different from each other in advance.

Further, information detecting means for detecting information on the vibration transmission characteristic from the vibration source to the vibration eliminating position, and when the predetermined information is detected by this information detecting means, the above-mentioned detection is made from a plurality of types of fixed filters. Switching means for selectively switching the fixed filter corresponding to the information.

According to the tenth aspect of the invention, in manufacturing the active vibration control device of the fourth or fifth aspect, it is impossible to describe the adaptive filter based on the vibration transfer characteristic from the vibration source to the vibration elimination position in advance. In this method, the frequency domain is measured, a fixed filter describing the signal waveform in the undescribed frequency domain is prepared, and the fixed filter is connected to the signal input side of the adaptive filter.

According to the eleventh aspect of the present invention, when the active vibration control device of the fourth, fifth or sixth aspect is manufactured, the cepstrum analysis is applied to the vibration transfer function of the controlled object for which the vibration is to be eliminated. Two transfer functions suitable for processing by the filter and the fixed filter are extracted, and the adaptive filter and the fixed filter are designed based on these two transfer functions.

[0025]

With the above construction, according to the invention of claim 1, the vibration of the vibration source is basically detected by the vibration detecting means and the reference signal is output in accordance with the operation of the active vibration control device. Is input to the adaptive filter. In this adaptive filter, the reference signal from the vibration detecting means is processed and an anti-vibration signal having the same amplitude as the vibration signal but having the opposite phase is output to the vibrating means, and the vibrating means causes anti-vibration. At the vibration erasing position, the vibration from the vibration source and the anti-vibration from the vibrating means cancel each other out, so that the vibration at the vibration erasing position can be erased. Also, at the vibration erasing position, the error vibration that could not be erased is monitored by the monitor means,
The adaptive filter is controlled by the control means that receives the monitor signal from the monitor means so as to reduce the error vibration at the vibration elimination position based on the monitor signal, and the filter coefficient is sequentially updated and optimized. It

At this time, the limiting means limits the reference signal processed by the adaptive filter to a predetermined frequency range. For this reason, for example, it is possible to prevent a reference signal in a frequency domain having a complicated transfer characteristic from being input to the adaptive filter, and stop the adaptive function of the adaptive filter in the complex frequency domain, and the reference signal remains unchanged. It is possible to prevent the deterioration of the vibration erasing performance due to the vibration erasing failure when input to the adaptive filter.

Further, due to such a limitation of the reference signal, the reference signal in the frequency domain having a simple transfer characteristic is inputted to the adaptive filter, so that the resolution thereof is low and the low cost adaptive filter is used. Cost reduction can be achieved.

According to the second aspect of the invention, since the limiting means is a filter, the limiting means having the above function can be easily obtained.

In the third aspect of the invention, the limiting means is a fixed filter, and the fixed filter has a signal waveform in a predetermined frequency region different from the frequency region of the reference signal processed by the adaptive filter described in advance. The reference signal in the frequency domain having a complicated transfer characteristic, which is not processed by the adaptive filter, can be processed by the signal waveform described in advance in the fixed filter in the fixed filter, and the vibration reduction performance can be improved.

According to the invention of claim 4, the fixed filter describes a signal waveform in a predetermined frequency region in which the adaptive filter cannot describe. Therefore, the reference signal which is not processed by the adaptive filter is accurately processed by the fixed filter. be able to.

According to the fifth aspect of the invention, as in the first aspect of the invention, the reference signal output from the vibration detecting means is input to the adaptive filter and processed, and the anti-vibration having the same amplitude as the opposite phase of the vibration signal. The signal is output to the vibrating means, the vibration is erased by the vibration from the vibration source and the anti-vibration from the vibrating means at the vibration eliminating position, and the adaptive filter is controlled based on the error vibration that cannot be eliminated. , The filter coefficient is sequentially updated and optimized.

At this time, since a fixed filter describing a waveform signal in a predetermined frequency region where the adaptive filter cannot describe is arranged in series with the adaptive filter on the upstream side of the adaptive filter, it is processed by the adaptive filter. A fixed filter can accurately process unreferenced reference signals.

The fixed filter on the upstream side of the adaptive filter prevents the reference signal in the frequency region having a complicated transfer characteristic from being input to the adaptive filter, and the function of the adaptive filter is stopped in the complicated frequency region. It is possible to prevent the deterioration of the vibration elimination performance. Further, since the frequency domain reference signal having a simple transfer characteristic is input to the adaptive filter, it is possible to reduce the cost by using the low cost adaptive filter.

In the sixth aspect of the invention, the fixed filter is provided in parallel with the adaptive filter, and the frequency band of the signal waveform described by the fixed filter and the frequency band of the signal waveform described by the adaptive filter are different. The fixed filter can process only the frequency region having a complicated transfer characteristic in the reference signal, and the adaptive filter can process only the frequency region other than the frequency region having a complicated transfer characteristic.

According to the invention of claim 7, the fixed filter is an analog filter which is cheaper than the digital filter, so that the cost can be further reduced.

According to the invention of claim 8, the information detecting means detects that the vibration transfer characteristic from the vibration source to the vibration elimination position has changed from the vibration transfer characteristic corresponding to the signal waveform described in the fixed filter. Then, the prohibiting means prohibits the operation of the fixed filter. That is, even if the actual vibration transfer characteristics from the vibration source to the vibration elimination position change and deviate from the characteristics of the fixed filter, the operation itself of the fixed filter is prohibited, so that it is possible to prevent deterioration of the vibration reduction performance. Can be prevented.

According to the ninth aspect of the invention, when the information detecting means detects the predetermined information from the information relating to the vibration transfer characteristic from the vibration source to the vibration eliminating position, the switching means selects from among a plurality of types of fixed filters. The fixed filter corresponding to the detection information is selectively switched. For this reason, a fixed filter that is optimum for the vibration transmission characteristic from the vibration source to the vibration elimination position can be obtained, so that the vibration reduction performance can be improved.

According to the tenth aspect of the present invention, for example, when mass-producing the vibration control target, the vibration transfer characteristics from the vibration source to the vibration elimination position are checked in advance at the trial production stage.
Based on the vibration transfer characteristics, the frequency range of the adaptive filter that cannot be described is measured, and a fixed filter that describes the signal waveform of the frequency range that cannot be described is prepared, and then fixed during mass production. It is only necessary to connect the filter to the signal input side of the adaptive filter, which simplifies the manufacture of the active vibration control device.

In the eleventh aspect of the present invention, the cepstrum analysis is performed on the vibration transfer function of the controlled object, which is suitable for processing by the adaptive filter and the fixed filter, respectively.
Two transfer functions are extracted. Then, since the adaptive filter and the fixed filter are designed based on the both transfer functions, it is possible to quickly design the appropriate adaptive filter and the fixed filter corresponding to the vibration transfer characteristic of the controlled object.

[0040]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) In FIG. 3, reference numeral 1 is a vehicle body, an engine room 2 is provided in a front portion thereof, and a vehicle compartment 3 is provided in a front and rear central portion thereof, and an instrument panel 4 at a front end of the vehicle compartment 3 is provided. An air conditioner 5 is disposed in the air conditioner 5. The air conditioner 5 has a blower 6 as a noise source, and a detection as vibration detecting means for detecting the noise and outputting a reference signal in the vicinity of the blower 6. A microphone 7 is provided. In addition, left and right front seats 8 and 8 are installed in the front part of the vehicle interior 3, and left and right rear seats 9 and 9 are installed in the rear part, respectively, and the ears of passengers seated in these seats 8 and 9 are installed. The vicinity of is the noise elimination position (vibration elimination position). Reference numeral 2a is a door, and 12 is a steering wheel located in the front part of the vehicle interior 3.

Eight monitor microphones 10, 10, ... As monitor means are provided at predetermined positions in the vehicle compartment 3.
Two speakers 11 and 11 as a vibrating means are arranged respectively. Monitor microphones 10, 10,
Is installed in a vibration elimination position near the ears of the occupants seated on the front seats 8 and the rear seats 9, and is installed in the seats 8 and 9 by the monitor microphones 10. Error noise at (vibration elimination position) is detected for monitoring.

On the other hand, the two speakers 11 and 11 are installed on the instrument panel 4 as audio speakers, so that the speakers 11 and 11 generate reversal sound or audio sound to be supplied into the passenger compartment 3. Has become.

The speakers 11 are connected to a controller 13 installed on the instrument panel 4.
The controller 13 is for performing noise reduction control. The controller 13 includes the output signal from the detection microphone 7 and the eight monitor microphones 1.
Output signals from 0, 10, ... and noise reduction control ON /
At least the switching signal of the changeover switch 14 for switching between OFF and noise reduction control and operation of the audio unit (not shown) is inputted, and the controller 13 basically sets a predetermined value in the blower 6 as a noise source. An anti-noise having a phase opposite to the noise of the frequency component is generated according to the transfer characteristics of the sound from each speaker 11 between the speaker 11 and each monitor microphone 10 at the noise elimination position, and the noise at the noise elimination position is generated. I am trying to erase.

The internal structure of the controller 13 is shown in FIG. In the figure, 15 is the detection microphone 7 described above.
It is an amplifier that amplifies the reference signal from. 16
Is an amplifier for amplifying the monitor signal from each monitor microphone 10, and 17 is an amplifier for converting the analog monitor signal amplified by each amplifier 16 into a digital signal.
It is a / D converter. Reference numeral 18 is a control block to which the output signal from the amplifier 15 and the signal from each A / D converter 17 are input. The control block 18 is arranged to reduce the noise detected by each monitor microphone 10. A speaker output signal for driving and controlling the speaker 11 is generated.

Further, 19 is a D / A converter for converting each speaker output signal generated in the control block 18 from a digital value to an analog value, and 20 is each D / A converter 1
An amplifier that amplifies the speaker output signal from 9,
The speaker output signal amplified by each amplifier 20 is output to each speaker 11. With the above configuration, anti-noise having a phase opposite to the noise of the predetermined frequency component in the blower 6 as a noise source is generated from each speaker 11 between the speaker 11 and each monitor microphone 10 at the noise elimination position. The noise is reduced according to the transfer characteristic to reduce the noise at the noise elimination position.

The structure of the control block 18 will be described with reference to FIG. 1. Reference numeral 21 is an A / D converter for converting the analog reference signal from the detection microphone 7 amplified by the amplifier 15 into a digital signal. Processes the reference signal from the A / D converter 21 and outputs an anti-vibration signal of the same amplitude as the noise signal of the blower 6 in the opposite phase to each speaker 11 via each of the D / A converters 19. The adaptive filter is a digital filter. Reference numeral 23 is a control unit for controlling the adaptive filter 22, which is based on the reference signal from the detection microphone 7 via the A / D converter 21 and the monitor signal from the monitor microphone 10 via the A / D converter 17. ,
The adaptive filter 22 is controlled by, for example, an LMS adaptive algorithm so that the error noise at the noise elimination position is reduced, and the filter coefficient of the adaptive filter 22 is sequentially updated and optimized.

A feature of the present invention is that the signal input system transmitted from the detection microphone 7 to the adaptive filter 22, that is, upstream of the adaptive filter 22 and between the amplifier 15 and the A / D converter 21. A fixed filter 24 composed of an analog filter describing a predetermined signal waveform is connected in series to the adaptive filter 22. The fixed filter 24 is used as the adaptive filter 22 in advance.
Describes a signal waveform of a predetermined frequency region different from the frequency region of the reference signal processed by, specifically, a signal waveform of a predetermined frequency that cannot be described by the adaptive filter 22, and the fixed filter 24 processes the signal waveform by the adaptive filter 22. The reference signal generated is limited to a predetermined frequency range. The signal waveform of the predetermined frequency that cannot be described by the adaptive filter 22 is substantially uniformly determined according to the transfer characteristic of the noise in the vehicle interior from the blower 6 to the noise elimination position (the position of each monitor microphone 10), and is fixed. Filter 24
In the case of determining the signal waveform described in (1), the undescriptable frequency region of the adaptive filter 22 is measured based on the noise transfer characteristic from the blower 6 to the noise elimination position in advance at the stage of trial manufacture of the vehicle. Then, the fixed filter 24 in which the signal waveform in the undescribed frequency domain is described is prepared. Then, after that, the fixed filter 24 may be connected to the signal input side of the adaptive filter 22. This way
The fixed filter 24 having a preset characteristic is used as the adaptive filter 2
It is only necessary to connect the two to the signal input side, and the active vibration control device of this embodiment can be easily manufactured.

A method of designing the fixed filter 24 (analog filter) and the adaptive filter 22 (digital filter) will be described with reference to FIG.
As shown in FIG. 6A, the vibration transfer function of the controlled object from which the vibration is to be eliminated is derived from the measured values, and then, as shown in FIG. Impulse response time length t
1 (one obtained by multiplying the sampling period, that is, the reciprocal of the sampling frequency fs by the tap length Ltap) is input as a parameter, and the cepstrum analysis is performed on the above transfer function. In this cepstrum analysis, after taking the logarithm of the spectrum of the transfer function, an inverse Fourier transform is performed to obtain a cepstrum with the kefrenshi as an axis, and this cepstrum is Fourier transformed back to the spectrum. A transfer function suitable for processing by the adaptive filter 22 (digital system) as shown in FIG. 6C and a kefrenc component having an impulse response time t1 or more are used by using a kefrenc component having a time t1 or less. As shown in FIG. 6D, the transfer function suitable for processing by the fixed filter 24 (analog system) is extracted. Then, the adaptive filter 22 and the fixed filter 24 are designed based on these transfer functions. Incidentally, since the specifications of the digital system are extracted at the stage of inputting the impulse response time length t1 as a parameter in the cepstrum analysis, the design of the adaptive filter 22 is mainly performed for the verification of the suitability of the analog system. .

FIG. 7 is a characteristic diagram specifically showing the characteristics of the two transfer functions extracted by the above cepstrum analysis. By the cepstrum analysis of the transfer function to be controlled, digital conversion is performed using the short kefrenc component of the transfer function. The transfer function represented by the system and the transfer function represented by the analog system are extracted by using the long Kefrenshi component of the transfer function.
Based on the above, the adaptive filter 22 and the fixed filter 24 are designed.

By designing the digital and analog systems using the cepstrum analysis of the transfer function in this way, the adaptive filter 22 and the fixed filter 24 can be designed easily and quickly.

Therefore, in the above embodiment, the noise from the blower 6 of the vehicle air conditioner 5 is detected by the detection microphone 7 with the changeover switch 14 in the passenger compartment 3 switched to the noise control position. The detection signal is output from the microphone 7 as a reference signal, and this reference signal is input to the control block 18 of the controller 13. Further, each monitor microphone 10 in the passenger compartment 3 detects noise near the ears of the passenger in the passenger compartment 3, and the output signal of each monitor microphone 10 is also input to the control block 18. In the control block 18, the reference signal from the detection microphone 7 is processed by the adaptive filter 22 to generate a speaker output signal for reducing noise detected by each monitor microphone 10, and the speaker output signal is output to each speaker. 11 is output to each of the speakers 11,
Anti-noise having the same amplitude as that of the blower noise consisting of high-band random noise is generated in the opposite phase, and the anti-noise from the speaker 11 and the noise from the blower 6 are mutually at the noise elimination positions near the occupants' ears. They cancel each other out, which reduces the blower noise at the noise elimination position.

At each vibration elimination position, the error noise that could not be eliminated is detected by the monitor microphone 10, and the control unit 23 reduces the error noise at the noise elimination position based on the monitor signal from the monitor microphone 10. As described above, the filter coefficient of the adaptive filter 22 is sequentially updated and optimized.

At this time, a fixed filter 24 in which a signal waveform is described in advance is connected in series to the input side of the adaptive filter 22, and the description signal waveform of the fixed filter 24 has a predetermined frequency which the adaptive filter 22 cannot describe. Since the signal waveform is a signal waveform, even if the adaptive filter 22 has an undescriptable frequency range of the signal waveform that is determined according to the noise transfer characteristic in the vehicle interior from the blower 6 to the noise elimination position (position of each monitor microphone 10). The reference signal in the frequency domain can be properly and accurately processed by the fixed filter 24. As a result, the function of the adaptive filter 22 stops in the frequency domain of the signal waveform that the adaptive filter 22 cannot describe, and noise cancellation failure occurs when the reference signal of the undescribed signal waveform is directly input to the adaptive filter 22. Can be prevented, and the noise reduction performance can be improved.

Further, since the reference signal in the frequency domain of the undesired signal waveform is not input to the adaptive filter 22 as described above, its resolution is low and the cost is reduced by using the low-priced adaptive filter 22. Can be realized. Moreover, since the fixed filter 24 is an analog filter that is cheaper than a digital filter,
The cost can be further reduced.

Incidentally, FIG. 4 specifically shows the sound deadening effect of the above-mentioned embodiment.
When the N state is set, the muffling performance is improved as compared with the OFF state, but the muffling performance is deteriorated on the contrary in a predetermined frequency region (range shown by A in the figure). However, it can be seen that when the fixed filter 24 of the above embodiment is inserted, the sound deadening performance in the above frequency range is improved.

In the above embodiment, the fixed filter 24 describing the undesired signal waveform of the adaptive filter 22 is used, but instead of this, only the signal in the predetermined frequency region described in the adaptive filter 22 is used. It is also possible to use a low-pass filter, a high-pass filter, a band-pass filter or the like that passes the reference signal. In short, it is sufficient to provide a limiting means for limiting the reference signal processed by the adaptive filter 22 so as to be in the predetermined frequency range.

(Second Embodiment) FIG. 8 shows a second embodiment of the present invention. Since the basic structure of each of the following embodiments is the same as that of the first embodiment, the same parts as those in the drawings of the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

In this embodiment, attention is paid to the fact that the sound transmission characteristic from the blower 6 to the noise elimination position changes to some extent according to the open / closed state of the door of the automobile, and accordingly the operation of the fixed filter 24 is turned ON / OFF. It is designed to be switched.

That is, in the second embodiment, although not shown, the controller 13 receives a detection signal of a sensor for detecting the open / closed state of each door 2a of the automobile. FIG. 8 shows a control operation performed by the controller 13. First, in step S1, the opening information of the door 2a based on the output signal of the sensor, specifically, for example, the number of the doors 2a in the open state, the opening information. The position of the door 2a thus opened, its opening degree, etc. are sensed, and in step S2, it is determined whether or not a transfer characteristic far from the characteristic of the analog system using the fixed filter 24 is predicted from the door information. If this determination is NO, the process proceeds to step S3,
As in the first embodiment, the so-called hybrid ANC system that operates both the fixed filter 24 of the analog filter and the adaptive filter 22 of the digital filter is operated.
Set to N state.

On the other hand, if YES is determined in the step S2, the process proceeds to a step S4 and the fixed filter 24 is turned off.
In the F state, the operation of the analog system is prohibited, and then in step S5, the digital ANC system that operates the adaptive filter 22 of the digital filter is turned on.

Therefore, in this embodiment, the above step S
1 and S2, it is detected that the noise transfer characteristic from the blower 6 to the noise elimination position has changed from the noise transfer characteristic corresponding to the signal waveform described in the fixed filter 24 with the change of the open state of the door 2a. The information detecting means 41 is configured.

Further, the step S4 constitutes the prohibiting means 42 for prohibiting the operation of the fixed filter when the information detecting means 41 detects the change in the noise transmission characteristic due to the change in the open state of the door 2a.

In this embodiment, door opening information such as the number of open doors, the position of the open door, and the opening thereof is determined based on the output signal of the sensor, and the transfer information which is far from the characteristics of the analog system is determined by this door information. When not predicted, both the analog fixed filter 24 and the digital adaptive filter 22 are activated. In this case, the same effect as that of the above embodiment can be obtained.

However, when the transfer information that is far from the characteristics of the analog system is predicted from the door information, the fixed filter 24 is turned off to prohibit the operation of the analog system, and the digital ANC that operates only the adaptive filter 22. The system is turned on. For this reason,
Even if the actual noise transmission characteristic from the blower 6 to the noise elimination position changes due to the change of the open state of the door 2a and deviates from the characteristic of the fixed filter 24, the fixed filter 24
Does not work, it is possible to favorably prevent the noise reduction performance from deteriorating.

In this embodiment, the analog system is switched off based on the open state of the door 2a, but in addition, for example, the open state of the windows, the front and rear positions of the seats 8 and 9, their reclining information, and the passenger compartment. The temperature and the like in 3 are respectively sensed, and when there is a possibility that they may be far from the characteristics of the analog system, the operation of the analog system may be prohibited, and the same effect can be obtained.

(Embodiment 3) FIGS. 9 and 10 show Embodiment 3 in which when the air conditioning mode in the vehicle-mounted air conditioner 5 is switched, the corresponding analog system is changed and switched. .

That is, in this embodiment, although not shown, the first and second fixed filters are provided as the fixed filter 24, and these are connected in parallel to the input side of the adaptive filter 22. The analog system I is turned on when the second fixed filter is stopped and only the first fixed filter is operated, and the analog system II is stopped when the first fixed filter is stopped and the second fixed filter is operated. Is turned on. As shown in FIG. 10 (a), the first fixed filter is designed to reduce the noise in the vehicle interior 3 when the damper (not shown) of the air conditioner 5 is in the inside air switching position for sucking the inside air in the vehicle interior 3. The signal waveform corresponding to the transfer characteristic is described, while the second fixed filter is shown in FIG.
As shown in 0 (b), a signal waveform corresponding to the same transfer characteristic when the damper is in the outside air switching position for sucking the outside air outside the vehicle is described.

In this embodiment, the controller 13
The processing operation in is performed as shown in FIG. First, in step T1, switching between inside and outside air is determined based on the switching position of the damper. If it is determined to be the inside air switching position, only the first fixed filter is operated in step T2 to operate the analog system I, and then the process returns.

On the other hand, when the determination in step T1 is the outside air switching position, the process proceeds to step T3, in which only the second fixed filter is operated to operate the analog system II, and then the process returns.

In this embodiment, the step T1 constitutes the information detecting means 43 for detecting the inside / outside air switching of the damper of the air conditioner 5 as the information on the noise transfer characteristic from the blower 6 to the noise elimination position.

Further, when the information of the inside air switching position or the outside air switching position of the damper is detected by the information detecting means 43 in steps T2 and T3, the damper switching position is selected from among the first and second fixed filters. A switching means 44 for selectively switching the corresponding fixed filter is configured.

Therefore, in this embodiment, switching of the inside / outside air is sensed based on the switching position of the damper in the air conditioner 5, and when it is determined to be the inside air switching position, only the first fixed filter is operated to operate the analog system. I operates, but when it is determined to be the outside air switching position, the second
The analog system II operates by operating only the fixed filter. In this way, two analog fixed filters are connected, and one of the two fixed filters is selected according to the switching between the inside and outside air. Therefore, the selected fixed filter is optimal for the noise transfer characteristic from the blower 6 to the noise elimination position. Will be met. Therefore, it is possible to improve the noise reduction performance regardless of switching between the inside and outside air of the air conditioner 5.

(Fourth Embodiment) FIGS. 11 and 12 show a fourth embodiment.
In the third embodiment, the analog system is selectively switched according to the switching of the inside / outside air of the air conditioner 5, whereas the analog system is selectively switched according to the temperature change in the passenger compartment. .

That is, the processing operation of the controller 13 in this embodiment will be described. As shown in FIG.
In step U1, input the information on the temperature t (° C) in the passenger compartment,
In step U2, the sound velocity v (m / sec) is calculated from this temperature t by the following equation.

V = 331.5 + 0.61t In the next step U3, the sound velocity v is multiplied by a predetermined constant to calculate the frequency f (Hz) of the cutoff region by the fixed filter 24. Input the frequency f0. Then, in step U5, it is determined whether or not the frequency f of the new cutoff region and the frequency f0 of the current cutoff region match, and if this determination is YES at f = f0, the process directly returns, but f ≠ f0 If NO in step U6, the frequency in the cutoff region is set to the current value f0 in step U6.
After changing from this time to the value f of this time, it returns.

In this embodiment, the above steps U1 to U5 are performed.
As a result, the information detecting means 43 for detecting the temperature change in the vehicle interior 3 is configured as the information regarding the noise transfer characteristic from the blower 6 to the noise elimination position.

In step U6, when the temperature change in the passenger compartment 3 is detected by the information detecting means 43,
The switching means 44 is configured so that the cutoff region of the fixed filter 24 is changed and the fixed filter corresponding to the room temperature is selected and switched from among substantially various types of fixed filters.

In the case of this embodiment, the sound velocity v is calculated according to the temperature t in the passenger compartment 3, the frequency f in the cutoff region by the fixed filter 24 is obtained, and the sound velocity v is changed with the change of the temperature t. When it changes, the frequency in the cutoff region is shown in FIG.
The current frequency f0 shown in (a) is switched to the new frequency f shown in (b). That is, even if the sound transmission characteristic changes due to the temperature change in the passenger compartment 3, the frequency of the cutoff region of the fixed filter 24 changes accordingly, so that the fixed filter 24 has a noise transmission characteristic from the blower 6 to the noise elimination position. Therefore, the noise reduction performance can be improved irrespective of temperature fluctuations, which is optimally adapted to temperature changes.

In the third and fourth embodiments, the air conditioner 5 is used.
In the case where the analog system is selectively switched according to the change of the inside / outside air and the temperature change in the vehicle compartment 3, a plurality of analog systems according to other situations are prepared,
You may make it select the most suitable analog system according to the situation from them. Examples of the above-mentioned situation include, for example, the open state of the door 2a and the window, the front and rear positions of the seats 8 and 9, the reclining information thereof, the occupant information, and the like.

(Fifth Embodiment) FIGS. 13 and 14 show a fifth embodiment.
, An analog system having a fixed filter 24 is provided in parallel with a digital system having an adaptive filter 22.

In this embodiment, as shown in FIG. 14, the transfer characteristic from the blower 6 to the noise elimination position is complicated in the low frequency region of the blower noise, whereas the transfer characteristic is simple in the high frequency region. Is the optimal system for
As shown in FIG. 13, in the controller 13, the fixed filter 24 is connected in parallel with the adaptive filter 22, and the output signals (speaker output signals) of both filters 22 and 24 are added by the adder 27 and then output to the speaker 11. To be done.

The adaptive filter 22 processes a reference signal in a high frequency region having a simple transfer characteristic, whereas the fixed filter 24 processes the reference signal processed by the adaptive filter 22. Unlike the high frequency region, the signal waveform in the low frequency region having a complicated transfer characteristic is described in advance.

Then, in order to divide the frequency band of the reference signal into the filters 22 and 24, the adaptive filter 2
A high-pass filter 28 that passes the high frequency region of the reference signal output from the detection microphone 7 is provided on the input side of 2, and an input side of the fixed filter 24 is passed the low frequency region of the reference signal. The low-pass filters 29 are connected to each other.

In this embodiment, of the reference signal output from the detection microphone 7, a signal in a high frequency region having a simple transfer characteristic in the vehicle interior 3 is blocked by the low-pass filter 29 and is fed to the fixed filter 24. It is not input but is input to the adaptive filter 22 via the high-pass filter 28, and anti-noise is generated. On the other hand, a signal in a low frequency region having a complicated transfer characteristic is blocked by the high-pass filter 28 and is not input to the adaptive filter 22, but is input to the fixed filter 24 via the low-pass filter 29 and is described in advance in the fixed filter 24. It is processed by the existing signal waveform.

Therefore, in this case, the fixed filter 24
And the adaptive filter 22 are made to function, and the fixed filter 24 processes only the low frequency region having a complicated transfer characteristic in the reference signal, and the adaptive filter 22 processes only the other high frequency region. it can.

(Sixth Embodiment) FIGS. 15 and 16 show a sixth embodiment.
The frequency regions processed by the fixed filter 24 and the adaptive filter 22 with respect to the reference signal are reversed from those in the fifth embodiment.

That is, in this embodiment, the above-mentioned embodiment 5 is used.
Unlike FIG. 16, the optimum system is used when the transfer characteristic from the blower 6 to the noise elimination position is complicated in the high frequency region of the blower noise, while the transfer characteristic is simple in the low frequency region as shown in FIG. And the adaptive filter 22
Is designed to process a low frequency region having a simple transfer characteristic. On the other hand, unlike the low frequency region of a reference signal processed by the adaptive filter 22, the fixed filter 24 has a complicated high transfer characteristic. The signal waveform in the frequency domain is described in advance.

As shown in FIG. 15, a low-pass filter 29 for passing the low frequency region of the reference signal is provided on the input side of the adaptive filter 22, and a reference signal of the reference signal is provided on the input side of the fixed filter 24. The high-pass filters 28 that pass the higher frequency region are connected to each other.

Therefore, in this embodiment, of the reference signal output from the detection microphone 7, the signal in the low frequency region where the transfer characteristic in the vehicle interior 3 is simple is cut off by the high-pass filter 28 and passed to the fixed filter 24. Is input to the adaptive filter 22 via the low-pass filter 29, and anti-noise is generated. On the other hand, a signal in a high frequency region having a complicated transfer characteristic is input to the high-pass filter 2.
8 is input to the fixed filter 24 and processed by the signal waveform described in advance in the fixed filter 24.
Also in this embodiment, the same operational effects as those of the above-mentioned fifth embodiment can be obtained.

Example 7 FIGS. 17 and 18 show Example 7
In this example, the adaptive filter 22 processes only the frequencies in the intermediate range with respect to the reference signal, and the signals in the other high and low frequency ranges are processed by the fixed filter.

In this embodiment, as shown in FIG. 18, the transfer characteristic from the blower 6 to the noise eliminating position is complicated in the high and low frequency regions excluding the intermediate frequency region of the blower noise, while the intermediate frequency region is Is an optimal system when the transfer characteristics are simple.

As shown in FIG. 17, in the controller 13, the two fixed filters 25 and 26 are the adaptive filters 2.
The output signals of the fixed filters 25 and 26 and the adaptive filter 22 are connected in parallel with the output signal of the filter 2, and are output to the speaker 11 after being added by the adder 27.

While the adaptive filter 22 processes the intermediate frequency region having a simple transfer characteristic, the fixed filter 25 on one side produces a signal waveform in a low frequency region having a complicated transfer characteristic. The other fixed filter 2
6 also describes in advance the signal waveforms in the high frequency region where the transfer characteristics are similarly complicated.

As shown in FIG. 18, the adaptive filter 22 has an input side provided with a bandpass filter 30 for passing the intermediate frequency region of the reference signal, and one fixed filter 25 provided with an input side. Low-pass filter 29 that passes the low frequency region of the reference signal
However, a high-pass filter 28 that passes a high frequency region is connected to the input side of the other fixed filter 26.

Therefore, in this embodiment, among the reference signals from the detection microphone 7, the signal in the intermediate frequency region having a simple transfer characteristic in the passenger compartment 3 is input to the adaptive filter 22 via the band pass filter 30. While the anti-noise is generated, a signal in a low frequency region having a complicated transfer characteristic passes through a low pass filter 29 to one fixed filter 25, and a signal in a high frequency region having a complicated transfer characteristic passes through a high pass filter 28. Each of the fixed filters 2 is input to the other fixed filter 26,
5, 26 are processed according to the signal waveforms described in advance. Therefore, also in this embodiment, the same operational effects as those of the above-mentioned Embodiments 5 and 6 can be obtained.

In each of the above embodiments, the blower noise of the air conditioner 5 is eliminated as the vehicle noise, but the present invention is of course adapted to eliminate noise other than the blower noise. It can also be applied to the ANC system. Further, in the above embodiment, the noise in the space inside the vehicle interior 3 of the automobile is erased, but it can also be applied to the case of silencing other spaces in the vehicle or general spaces other than the vehicle.

(Embodiment 8) FIG. 19 shows an embodiment 8. In each of the above embodiments, noise is treated as vibration, but in this embodiment, pure vehicle body vibration is eliminated.

Referring to FIG. 19, a detection upper / lower portion for detecting vertical vibration (a vibration source in this case is a suspension) input to the vehicle body 1 from the road surface via the right front wheel (not shown) is provided on the right front portion of the vehicle body 1. The acceleration sensor 31 is arranged,
The output signal of the vertical acceleration sensor 31 is input to the controller 13 as a reference signal. Further, for example, a vibration actuator 32 as a vibration means for vibrating the vehicle body 1 is attached to the rear portion of the engine room 2, and the vibration actuator 32 generates anti-noise vibration.

Further, similarly to each of the above-described embodiments, the positions of the occupants seated on the left and right front seats 5, 5 and the rear seats 6, 6 are set as the vibration elimination position, and the vibration elimination position is set to 4 as a monitor means. Vertical monitor acceleration sensors 33, 33, ...
Detects the error vibration at the installation location (vibration elimination position) for monitoring.

The actuator 32 and each monitor vertical acceleration sensor 33 are connected to the controller 13. The controller 13 processes the reference signal from the detection vertical acceleration sensor 31 to process the vehicle body 1.
Generates an anti-vibration signal having a phase opposite to that of the vibration of the actuator 32.
Vertical acceleration sensor 3 for each monitor in the vibration elimination position
The vibrations at the vibration eliminating positions are eliminated by generating the vibrations according to the vibration transmission characteristics between the vibrations 3, 3 ,.

The configuration of the controller 13 is the same as that of each of the above-described embodiments, and apart from the adaptive filter 22,
As a limiting means for limiting the reference signal processed by the adaptive filter 22 to a predetermined frequency range in the signal transmission system that is transmitted from the detection vertical acceleration sensor 31 to the adaptive filter 22, a signal in the predetermined frequency range from the reference signal is used. Only a filter that passes only, or a fixed filter 24 in which a signal waveform in a predetermined frequency region is described in advance.
Is provided.

Therefore, also in this embodiment, as in the case of the blower noise, the cost can be reduced and the vibration elimination performance can be improved and maintained by using the low-priced adaptive filter 22.

[0103]

As described above, according to the invention of claim 1, the vibration of the vibration source is detected and used as a reference signal, and this reference signal is processed to have a phase opposite to that of the vibration in the vibration source. The anti-vibration signal is output to the vibrating means, and the anti-vibration by this vibrating means erases the vibration from the vibration source at the vibration elimination position and monitors the error vibration at the vibration elimination position to reduce this monitor vibration. When the adaptive filter is controlled so that the reference signal processed by the adaptive filter is limited by the limiting means so that the reference signal is in the predetermined frequency region, the cost can be reduced by using the low-priced adaptive filter. In addition, the adaptive filter with low resolution does not sufficiently process the anti-vibration signal and the reference in the frequency domain has a complicated transfer characteristic. No. is prevented from being processed is input, it is possible to improve maintenance of the vibration erasing performance.

According to the second aspect of the present invention, since the limiting means is a filter which passes only the signal in the predetermined frequency region from the reference signal, the limiting means having the above function can be easily obtained.

According to the third aspect of the present invention, the limiting means uses the fixed filter in which the signal waveform in the predetermined frequency region different from the frequency region of the reference signal processed by the adaptive filter is described in advance, so that the limiting filter processes it. It is possible to process the reference signal in the frequency domain not to be processed by the signal waveform described in advance by the fixed filter, and it is possible to further improve the vibration reduction performance.

According to the fourth aspect of the present invention, the fixed filter describes the signal waveform in the predetermined frequency region in which the adaptive filter cannot describe. Therefore, the reference signal not processed by the adaptive filter is accurately processed by the fixed filter. Thus, the vibration reduction performance can be further improved.

According to the fifth aspect of the present invention, the fixed filter which describes the waveform signal of the predetermined frequency region where the adaptive filter cannot describe is arranged in series on the upstream side of the adaptive filter, so that the reference signal which is not processed by the adaptive filter is arranged. Can be accurately processed with a fixed filter, the reference signal in the frequency domain with a complicated transfer characteristic can be prevented from being input to the adaptive filter, and the function of the adaptive filter with respect to the complicated frequency domain can be stopped. By using a price adaptive filter, it is possible to prevent the deterioration of the vibration elimination performance while reducing the cost.

According to the invention of claim 6, the fixed filter is provided in parallel with the adaptive filter, and the frequency band of the signal waveform described by the fixed filter and the frequency band of the signal waveform described by the adaptive filter are made different. Thus, the reference signal only in the frequency region having a complicated transfer characteristic is processed by the fixed filter and the reference signal only in the other frequency region is processed by the adaptive filter, thereby improving the vibration reduction performance.

According to the invention of claim 7, the fixed filter is an inexpensive analog filter, which is advantageous for cost reduction.

According to the eighth aspect of the invention, when the vibration transfer characteristic from the vibration source to the vibration elimination position changes from the vibration transfer characteristic corresponding to the signal waveform described in the fixed filter, the fixed filter is activated. By prohibiting it, it is possible to favorably prevent deterioration of the vibration reduction performance even if the actual vibration transmission characteristic from the vibration source to the vibration elimination position changes and deviates from the characteristic of the fixed filter.

According to the ninth aspect of the present invention, the fixed filter has a plurality of signal waveforms which correspond to the vibration transfer characteristics from the vibration source to the vibration elimination position and which are different from each other in advance, and are arranged from the vibration source to the vibration elimination position. When predetermined information related to the vibration transfer characteristics of is detected, the fixed filter corresponding to the detected information is selectively switched from among a plurality of types of fixed filters, so that the vibration transfer characteristics from the vibration source to the vibration elimination position It is possible to improve the vibration reduction performance by selecting the optimum fixed filter for.

According to the tenth aspect of the present invention, the undescriptable frequency region of the adaptive filter is measured in advance based on the vibration transfer characteristic from the vibration source to the vibration elimination position, and the signal waveform of the undescriptable frequency region is measured. Prepared in advance, by connecting the fixed filter to the signal input side of the adaptive filter, for example, when mass-producing the vibration control target, the fixed filter is prepared in the trial production stage, In the subsequent mass production, it suffices to connect the fixed filter to the signal input side of the adaptive filter, and the active vibration control device can be easily manufactured.

According to the eleventh aspect of the present invention, the cepstrum analysis is performed on the vibration transfer function of the controlled object whose vibration is to be eliminated, and two transfer functions suitable for processing by the adaptive filter and the fixed filter are extracted. By designing the adaptive filter and the fixed filter based on these transfer functions, it is possible to quickly design the appropriate adaptive filter and fixed filter corresponding to the vibration transfer characteristics of the controlled object.

[Brief description of drawings]

FIG. 1 is a block diagram showing a control block of a controller according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of an active vibration control device and an internal configuration of a controller in the first embodiment.

FIG. 3 is a schematic diagram showing an overall configuration of an active vibration control device in the first embodiment.

FIG. 4 is a characteristic diagram showing a specific example of a sound deadening effect.

FIG. 5 is an explanatory diagram showing a procedure for designing a digital filter and an analog filter using cepstrum analysis of a vibration transfer function of a control target.

FIG. 6 is an explanatory diagram showing the principle of extracting two transfer functions from the vibration transfer function of the controlled object by cepstrum analysis.

FIG. 7 is a characteristic diagram specifically showing characteristics of two transfer functions extracted by cepstrum analysis.

FIG. 8 is a flowchart showing a signal processing operation performed by a controller in the second embodiment.

FIG. 9 is a flowchart showing a signal processing operation performed by a controller in the third embodiment.

FIG. 10 is a characteristic diagram showing a noise transfer characteristic in the third embodiment.

FIG. 11 is a flowchart showing a signal processing operation performed by a controller in the fourth embodiment.

FIG. 12 is a characteristic diagram showing characteristics of a fixed filter according to the fourth embodiment.

FIG. 13 is a block diagram showing an internal configuration of a controller in the fifth embodiment.

FIG. 14 is a characteristic diagram showing a frequency range in which an adaptive filter and a fixed filter operate in a fifth embodiment.

FIG. 15 is a view corresponding to FIG. 13 showing the sixth embodiment.

FIG. 16 is a view corresponding to FIG. 14 showing the sixth embodiment.

FIG. 17 is a view corresponding to FIG. 13 showing the seventh embodiment.

FIG. 18 is a view corresponding to FIG. 14 showing the seventh embodiment.

FIG. 19 is a view corresponding to FIG. 3 showing an eighth embodiment.

[Explanation of symbols]

 3 Car Room 5 Air Conditioner 6 Blower (Noise Source) 7 Detection Microphone (Vibration Detection Means) 10 Monitor Microphone (Monitor Means) 11 Speaker (Vibration Means) 13 Controller 18 Control Block 22 Adaptive Filter 23 Control Section (Control Means) 24, 25, 26 Fixed filter 31 Vertical acceleration sensor for detection (vibration detection means) 32 Vibration actuator (vibration means) 33 Vertical acceleration sensor for monitor (monitor means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location G10K 11/16 H03H 17/04 A 8842-5J 21/00 8842-5J (72) Inventor Hiroshi Uchida 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (11)

[Claims] 1. A vibration detecting means for detecting a vibration of a vibration source and outputting a reference signal, and a reference signal from the vibration detecting means is processed to output an anti-vibration signal having the same amplitude as a phase opposite to the vibration signal. Adaptive filter, a vibrating means for generating an anti-vibration by receiving an anti-vibration signal from the adaptive filter, a monitor means arranged at a vibration elimination position for monitoring an error vibration at the vibration elimination position, and the monitor In the active vibration control device, which comprises a control means for controlling the adaptive filter so that the error vibration at the vibration elimination position is reduced based on the monitor signal from the means, the vibration detection means transmits the vibration to the adaptive filter. The reference signal transmission system is provided with limiting means for limiting the reference signal processed by the adaptive filter to a predetermined frequency range. Active vibration control apparatus according to claim and. 2. The active vibration control device according to claim 1, wherein the limiting means is a filter that passes only a signal in a predetermined frequency region of the reference signal. 3. The active vibration control device according to claim 1, wherein the limiting means is a fixed filter in which a signal waveform in a predetermined frequency region different from the frequency region of the reference signal processed by the adaptive filter is described in advance. An active vibration control device characterized by. 4. The active vibration control device according to claim 3, wherein the fixed filter describes a signal waveform in a predetermined frequency region in which the adaptive filter cannot describe. . 5. A vibration detecting means for detecting a vibration of a vibration source and outputting a reference signal, and a reference signal from the vibration detecting means is processed to output an anti-vibration signal having the same amplitude as a phase opposite to the vibration signal. Adaptive filter composed of a digital filter, a vibrating means for generating anti-vibration by receiving an anti-vibration signal from the adaptive filter, and a monitor means arranged at a vibration elimination position for monitoring error vibration at the vibration elimination position. And a control means for controlling the adaptive filter so that the error vibration at the vibration elimination position is reduced based on the monitor signal from the monitor means. On the side, a fixed filter that describes a waveform signal in a predetermined frequency range that the adaptive filter cannot describe is placed in series with the adaptive filter. Active vibration control device according to symptoms. 6. A vibration detecting means for detecting a vibration of a vibration source and outputting a reference signal, and a reference signal from the vibration detecting means is processed to output an anti-vibration signal having the same amplitude as a phase opposite to the vibration signal. Adaptive filter, vibration applying means for receiving anti-vibration signals from the adaptive filter to generate anti-vibration, monitor means arranged at a vibration elimination position for monitoring error vibration at the vibration elimination position, and the monitor In an active vibration control device including a control means for controlling the adaptive filter so as to reduce error vibration at a vibration elimination position based on a monitor signal from the means, a frequency of a reference signal processed by the adaptive filter. A fixed filter in which a signal waveform in a predetermined frequency region different from the region is described in advance is provided in parallel with the adaptive filter. The frequency band of that signal waveform,
An active vibration control device characterized by being different from the frequency band of a signal waveform described by an adaptive filter. 7. The active vibration control device according to claim 3, 4, 5 or 6, wherein the fixed filter is an analog filter. 8. The active vibration control device according to claim 3 or 4, wherein the vibration transfer characteristic from the vibration source to the vibration elimination position is changed from the vibration transfer characteristic corresponding to the signal waveform described on the fixed filter. An active vibration control device comprising: an information detecting means for detecting the above; and a prohibiting means for prohibiting the operation of the fixed filter when the change in the vibration transmission characteristic is detected by the information detecting means. 9. The active vibration control device according to claim 3 or 4, wherein a plurality of fixed filters are provided in advance, each of which has a signal waveform corresponding to a vibration transfer characteristic from a vibration source to a vibration elimination position and different from each other. When the predetermined information is detected by the information detection means for detecting the information on the vibration transfer characteristic from the vibration source to the vibration elimination position, and the information detection means,
An active vibration control device comprising: switching means for selectively switching a fixed filter corresponding to the detection information from a plurality of types of fixed filters. 10. The method for manufacturing the active vibration control device according to claim 4, wherein the adaptive filter cannot describe the frequency domain based on the vibration transfer characteristic from the vibration source to the vibration elimination position in advance. Is prepared and a fixed filter describing a signal waveform in the frequency domain that cannot be described is prepared, and the fixed filter is connected to the signal input side of the adaptive filter. Method. 11. The method for manufacturing the active vibration control device according to claim 4, 5, or 6, wherein a cepstrum analysis is performed on a vibration transfer function of a control target whose vibration is to be eliminated, thereby providing an adaptive filter and A method for manufacturing an active vibration control device, comprising: extracting two transfer functions suitable for processing by a fixed filter, and designing an adaptive filter and a fixed filter based on the two transfer functions.