JP2010286684A - Active vibration noise control device - Google Patents

Abstract

An object of the present invention is to reduce noise by dividing a space in the process of vibration noise spreading in the space and suppressing the secondary vibration in a stage where the structure becomes a secondary vibrating body.
An active vibration noise control apparatus according to the present invention includes secondary vibration detection means for detecting vibration of a boundary surface, and primary noise caused by vibration of a noise source is propagated to the boundary surface. A vibration generating means 6 installed on the boundary surface 3 and a secondary vibration detecting means, which is installed between the first space to be transmitted and the second space in which secondary noise propagates through the secondary vibration of the boundary surface 3. 7 is further provided with signal processing means 10 for generating a cancellation vibration signal from the detection result at 7 and drive control means 9 for causing the vibration generation means 6 to generate a cancellation vibration with respect to the vibration of the boundary surface 3 corresponding to the cancellation vibration signal. .
[Selection] Figure 5

Description

  The present invention relates to an active vibration noise control device, and more particularly to an active vibration noise control device that reduces vibrations and noise of devices or noises resulting from vibrations of devices.

  Other detection microphones installed at predetermined positions by detecting the air propagation sound of the noise emitted from the noise source with a microphone and outputting the air propagation sound in the opposite phase to the air propagation sound of the noise from the speaker Active noise control (ANC: active noise control) is known which reduces noise detected in the system.

  As such an ANC, one that reduces fan noise installed in an air conditioning duct by speaker output is known. As an example, Patent Document 1 calculates based on the noise detected by the microphone M1 located on the upper side of the noise propagation, and detects in the microphone M2 located on the lower side of the noise propagation by the sound output from the speaker S. A technique for reducing sound is disclosed.

  Here, the output of the speaker S is adjusted so as to have an opposite phase to the air propagation sound from the noise source at the position of the microphone M2. That is, arithmetic processing for adaptively changing the output of the speaker S little by little is performed so that the sound detected by the microphone M2 is minimized.

  On the other hand, Patent Document 2 discloses a technique for reducing noise caused by propagation from a noise source in an open space instead of noise propagation in a closed space such as a duct. A microphone that detects noise from a noise source, a speaker that outputs sound for reducing the noise detected by the microphone, and a sound that is output from the speaker according to the noise detected by the microphone A plurality of muffler units constituted by drive signal generators are arranged to reduce noise spreading in the space. In this way, the interference sound from the plurality of silencer units is adjusted so that the wavefronts are in phase and in phase with the noise from the noise source, and noise is reduced in the open space.

Japanese Patent Publication No. 8-27634 JP 2003-66969 A

  However, in the example of Patent Document 1, it is effective when noise propagates in a closed space such as a duct, and when noise from a noise source is to be reduced in an open space. Can not expect the effect.

  Further, in the example of Patent Document 2, it is intended to reduce noise generated in an open space, and the wave fronts of interference sounds emitted from a plurality of silencer units are aligned so that the noise from the noise source is reversed in a wide range. It is intended to reduce noise by building a phase relationship, but it is difficult to satisfy the antiphase relationship over a wide frequency range for noise once released into space, and low frequency noise with a long period It will be limited to obtaining the reduction effect with respect to. In addition, since a plurality of silencer units are arranged in an array, the system must be a large-scale and high-cost system.

  On the other hand, when considering the noise of equipment, the place where the noise is generated is the vibration derived from the eccentricity of the rotating part such as the motor, the vibration accompanying the movement of the moving part, the friction of the bearing, the vortex sound of the fluid, and the mechanical resonance accompanying them In some cases, it may occur in combination, but the source is limited to a specific site. The vibration of the specific part expands as noise, and as a result, the noise spreads in the space. The method of Patent Document 1 cannot deal with noise spread in space, and the method of Patent Document 2 can easily cope with the movement of the noise source, but the effect is low but it is easy to maintain an antiphase relationship. There is a problem that it is limited to frequency sound.

  The present invention has been made to solve the above-described problems, and suppresses the secondary vibration in the stage where the noise is spread and the structure becomes the secondary vibrator in the process of spreading the noise in the space. Thus, noise is reduced in a wide frequency range.

  An active vibration noise control device according to the present invention includes secondary vibration detection means for detecting vibration of a boundary surface, and the boundary surface includes a first space in which primary noise caused by vibration of a noise source propagates, and It is installed between the second space where the secondary noise propagates through the secondary vibration of the boundary surface, and the vibration generation means installed on the boundary surface and the cancellation vibration from the detection result in the secondary vibration detection means. Signal processing means for generating a signal, and drive control means for causing the vibration generating means to generate a canceling vibration corresponding to the vibration of the boundary surface corresponding to the canceling vibration signal.

  The active vibration noise control device according to the present invention includes secondary vibration detection means for detecting the vibration of the boundary surface, and the boundary surface includes a first space in which the primary noise caused by the vibration of the noise source propagates. , Installed between the second space where secondary noise propagates through the secondary vibration of the boundary surface, from the vibration generation means installed on the boundary surface, and the detection result in the secondary vibration detection means, Further comprising: signal processing means for generating a canceling vibration signal; and drive control means for generating a canceling vibration in the vibration generating means in response to the canceling vibration signal in the vibration generating means. In the process where noise becomes noise and diffuses into the first space and the second space, the secondary vibration that is the source of the noise is suppressed at the boundary surface, so that the noise generated by the device can be reduced over a wide frequency range. It is possible to result reduced.

1 is a basic configuration diagram of an active vibration noise control apparatus showing Embodiment 1 of the present invention. FIG. It is the block block diagram which showed the signal processing means which produces | generates the control vibration in Embodiment 1 of this invention. It is explanatory drawing supplementing the basic composition of the active vibration noise control apparatus concerning Embodiment 1 of this invention. It is another explanatory drawing which supplements the basic composition of the active vibration noise control apparatus concerning Embodiment 1 of this invention. It is a basic block diagram of the active vibration noise control apparatus which shows Embodiment 2 of this invention. It is the block block diagram which showed the signal processing means which produces | generates the control vibration in Embodiment 2 of this invention. It is a wave form diagram for demonstrating the method of calculating the vibration to suppress from the vibration after interference in Embodiment 2 of this invention. It is a block block diagram for demonstrating the method of estimating the control vibration of Embodiment 2 of this invention. It is explanatory drawing supplementing the basic composition of the active vibration noise control apparatus concerning Embodiment 2 of this invention. It is another explanatory drawing which supplements the basic composition of the active vibration noise control apparatus concerning Embodiment 2 of this invention. It is a figure which shows the other example of application of the active vibration noise control apparatus concerning Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a basic configuration diagram of an active vibration noise control apparatus according to Embodiment 1 of the present invention. In FIG. 1, a noise source 1 in which an original vibration that is a source of noise is inherent, a base surface 2 on which the noise source 1 is held, a first space in which primary noise caused by vibration of the noise source 1 propagates, It is installed between the second space where the secondary noise propagates through the secondary vibration of the surface, and the boundary surface 3 and the listener 4 are shown. The primary noise radiated from the noise source 1 is shown. A secondary vibration is generated in the process of propagating on the boundary surface 3 and is emitted in the form of secondary noise, reaches the listener 4 and is recognized as noise.

  Furthermore, the original vibration detecting means 5 for detecting the original vibration of the noise source 1 that is disposed close to or in close proximity to the noise source 1 and the secondary vibration of the boundary surface 3 that is disposed in close contact with the boundary surface 3 are in reverse phase. Vibration generating means 6 for generating the vibration, secondary vibration detecting means 7 for detecting the vibration of the boundary surface 3 disposed close to or in close contact with the boundary surface 3, and the output and secondary vibration of the original vibration detecting means 5 The output of the detecting means 7 is used as an input, and the signal processing means 8 for generating a canceling vibration signal for canceling the vibration of the boundary surface 3 used for the vibration generating means 6 from the detection result; Drive control means 9 for driving 6 is shown. In the drawing, the boundary surface 3 is arranged so as to be in contact with the base surface 2, but it may not be in contact.

  FIG. 2 shows a block diagram of the signal processing means 8 in FIG. The electric signals input from the original vibration detecting means 5 and the secondary vibration detecting means 7 are amplified to appropriate signal levels by the input amplifier 11 and the input amplifier 13, respectively, and are respectively A / D converter 12 and A / D converter. 14 converts the analog signal into a digital signal. The digital signal output from the A / D converter 12 is input to the FIR filter 16 and the LMS algorithm 15. The digital signal output from the A / D converter 14 is input to the LMS algorithm 15.

  In the FIR filter 16, the original vibration of the noise source 1 detected by the original vibration detection means 5 reaches the boundary surface 3 as primary noise and becomes secondary vibration, which is detected by the secondary vibration detection means 7. A control signal that has been corrected to have the same amplitude and opposite phase as the vibration to be generated is generated, converted from a digital signal to an analog signal by the D / A converter 17, and then converted to an appropriate signal level by the output amplifier 18. Amplified and output to the drive control means 9.

  Next, in FIG. 1 and FIG. 2, a method for suppressing secondary noise reaching the listener 4 will be described. The original vibration that forms the root of the primary noise radiated from the noise source 1 is detected by the original vibration detecting means 5 disposed close to or in close proximity to the noise source 1, and is input via the input amplifier 11 and the A / D converter 12. The digital signal is input to the FIR filter 16 and the LMS algorithm 15. At this time, the tap coefficient of the FIR filter is sequentially updated by the LMS algorithm 15. Further, the tap coefficient in the LMS algorithm 15 is updated in accordance with the equation 1 (h (n + 1) = h (n) + 2 · μ · e (n) · x (n)), and is optimal so that the error signal e approaches zero. The tap coefficient is updated.

  Here, h is a tap coefficient of the filter, e is an error signal, x is a filter input signal, and μ is a step size parameter. The step size parameter μ controls a filter coefficient update amount for each sampling.

  In this way, the digital signal that has passed through the FIR filter 16 whose tap coefficient has been updated by the LMS algorithm 15 is converted to an analog signal by the D / A converter 17, and an appropriate signal level is output by the output amplifier 18. And is converted into vibration by the vibration generating means 6 via the drive control means 9.

  On the other hand, in the secondary vibration detecting means 7 arranged close to or in close contact with the boundary surface 3, the vibration generating means 6 is converted into the secondary vibration generated when the primary noise radiated from the noise source 1 reaches the boundary surface 3. The vibration after causing the vibration generated by the above to interfere is detected. Further, since the vibration detected by the secondary vibration detecting means 7 is input to the error signal of the LMS algorithm 15 described above, the tap coefficient of the FIR filter 16 is updated so that the vibration after the interference approaches zero. Will be. As a result, the secondary vibration at the boundary surface 3 can be suppressed by the control vibration that has passed through the FIR filter 16, and the secondary noise that reaches the listener 4 can be reduced.

  The active vibration noise control described above is called a feed-forward control system, and in the process of suppressing the secondary vibration that becomes the source of the secondary noise in the process of the vibration becoming noise and diffusing into the space, Since the secondary vibration is suppressed based on the detection result of the noise source vibration, the noise generated by the device is effectively reduced over a wide band.

  3 and 4 are explanatory diagrams supplementing the basic configuration of the active vibration noise control apparatus according to Embodiment 1 of the present invention. Aside from the process in which primary noise is radiated from the noise source 1 and propagates through the space and reaches the boundary surface 3 to become secondary vibration, the original vibration propagates through the base surface 2 and reaches the boundary surface 3. The case where the secondary noise reaches the listener 4 based on the secondary vibration of the boundary surface 3 is shown together with the process of secondary vibration.

  The mechanism for reducing noise reaching the listener 4 is the same as described above, except that the energy of the original vibration reaches the boundary surface 3 through a plurality of paths. At this time, the secondary vibration detection means 7 can also detect the secondary vibration that has propagated solid through the base surface 2 as the installation surface where the noise source 1 is installed from the noise source 1 to the boundary surface 3. is there.

  Further, when solid vibration propagates on the base surface 2, the original vibration detection means 5 is not limited to being arranged close to or in close proximity to the noise source 1, and the original vibration is propagated as shown in FIG. You may arrange | position to the base | substrate surface 2 which is an installation surface to close or closely_contact | adhere.

  1, 3, and 4, the secondary vibration of the boundary surface 3 is described as a direction that is nearly perpendicular to the boundary surface 3, but the vibration is not limited to this direction, and is horizontal to the boundary surface. Needless to say, this is a composite vibration with a vibration component in the direction. Further, the vibration generating means 6 and the secondary vibration detecting means 7 are illustrated for convenience so that they are separated from each other. However, the present invention is not limited to this form. It doesn't matter.

  Specific examples of the original vibration detection means 5 and the secondary vibration detection means 7 include a method in which an acceleration sensor is configured in close contact with a detection target in order to detect vibration, and a method in which a capacitor microphone is configured in close proximity or in close contact. It is done. As a specific example of the vibration generating means 6, a configuration using a material that converts an electrical signal into mechanical vibration, such as an electric actuator, a piezoelectric actuator, or a giant magnetostrictive actuator, can be considered.

  On the other hand, in the first embodiment, the FIR filter 16 and the LMS algorithm 15 are used in the signal processing unit 8, but any adaptive signal processing circuit that brings the vibration detected by the secondary vibration detection unit 7 close to zero may be used. A filter-X algorithm that is generally used in an active muffling method may be used. Further, the signal processing means 8 may be configured to generate the control sound by a fixed tap coefficient instead of the adaptive signal processing. The signal processing means 8 may be an analog signal processing circuit instead of digital signal processing.

  According to the first embodiment of the present invention, in the active vibration noise control apparatus, the secondary vibration detection means 7 for detecting the vibration of the boundary surface 3 includes the noise source 1 installed from the noise source 1 to the boundary surface 3. By detecting also the secondary vibration that has propagated solid through the base surface 2 that is the installation surface, the vibration of the noise source 1 is propagated as solid noise in the process in which the vibration of the noise source 1 becomes noise and diffuses into the space. Since the secondary vibration which is the root of the noise including the vibration accompanying the noise is suppressed, the noise generated by the device can be effectively reduced in a wide frequency range.

  In addition, according to the first embodiment of the present invention, the active vibration noise control apparatus further includes the original vibration detecting means 5 for detecting the vibration of the noise source 1, and the signal processing means 10 includes the original vibration detecting means 5. And the secondary vibration detection means 7 generate a canceling vibration signal to suppress the secondary vibration that is the source of the noise in the process in which the vibration of the noise source 1 becomes noise and diffuses into the space. Since secondary vibration is suppressed by feedforward processing based on the detection result of vibration of the noise source 1 at the stage, noise generated by the device can be effectively reduced over a wide band.

  According to the first embodiment of the present invention, in the active vibration noise control apparatus, the original vibration detection means 5 is installed in the noise source 1 to detect the original vibration of the noise source 1 and to The vibration in the surface 3 can be suppressed and noise can be effectively reduced in a wide frequency range.

  Further, according to the first embodiment of the present invention, in the active vibration noise control apparatus, the original vibration detection means 5 is installed on the base surface 2 that is the installation surface on which the noise source 1 is installed. The original vibration of the noise source 1 can suppress the vibration that propagates through the solid, and the noise can be effectively reduced in a wide frequency range.

  Further, according to the first embodiment of the present invention, in the active vibration noise control apparatus, the vibration generating means 6 is an actuator, thereby generating a canceling vibration that cancels the vibration on the boundary surface 3. By suppressing the vibration in the noise, noise can be effectively reduced in a wide frequency range.

  Further, according to the first embodiment of the present invention, in the active vibration noise control device, the original vibration detection means 5 and the secondary vibration detection means 7 are acceleration sensors or microphones, so that the boundary surface 3 It is possible to detect vibrations and suppress the vibrations using canceling vibrations that cancel the vibrations, and to effectively reduce noise in a wide frequency range.

Embodiment 2. FIG.
FIG. 5 is a basic configuration diagram of an active vibration noise control apparatus according to the second embodiment of the present invention. The original vibration detecting means 5 and the secondary vibration detecting means 7 in the first embodiment are integrated into two parts. An active vibration noise control apparatus using only the secondary vibration detection means 7 will be described.

  In FIG. 5, the noise source 1 in which the original vibration that is the source of the noise is inherent, the base surface 2 on which the noise source 1 is held, the first space in which the primary noise caused by the vibration of the noise source 1 propagates, and the boundary It is installed between the second space where the secondary noise propagates through the secondary vibration of the surface, and the boundary surface 3 and the listener 4 are shown. The primary noise radiated from the noise source 1 is shown. A secondary vibration is generated in the process of propagating on the boundary surface 3 and is emitted in the form of secondary noise, reaches the listener 4 and is recognized as noise.

  Furthermore, the vibration generating means 6 is arranged in close contact with the boundary surface 3 to generate a vibration opposite in phase to the secondary vibration of the boundary surface 3, and the vibration of the boundary surface 3 is disposed in close proximity to or close to the boundary surface 3. The secondary vibration detecting means 7 for detecting the vibration, the signal processing means 10 for generating the canceling vibration signal for canceling the vibration of the boundary surface used for the vibration generating means 6 by using the output of the secondary vibration detecting means 7 and the signal processing means 8 A drive control means 9 is shown which receives the output and drives the vibration generating means 6 to generate a canceling vibration with respect to the vibration of the boundary surface 3. In the drawing, the boundary surface 3 is arranged so as to be in contact with the base surface 2, but it may not be in contact.

  The difference from the active vibration noise control apparatus described in the first embodiment is that in the first embodiment, the signal processing means 8 uses the vibration detection results of the original vibration detection means 5 and the secondary vibration detection means 7. In contrast to the generation of the control signal, the second embodiment is configured to use only the secondary vibration detection means 7. Further, since the signal processing method is different accordingly, the configuration contents of the signal processing means 10 are different.

  FIG. 6 shows a block diagram of the signal processing means 10 in FIG. The electric signal input from the secondary vibration detection means 7 is amplified to an appropriate signal level by the input amplifier 13 and converted from an analog signal to a digital signal by the A / D converter 14. The digital signal output from the A / D converter 14 is input to the LMS algorithm 15, and the difference signal from the signal obtained by convolving the FIR filter 19 with the output signal of the FIR filter 16 is input to the FIR filter 16 and the LMS algorithm 15. The

  This difference signal is subjected to a convolution operation with the tap coefficient calculated by the LMS algorithm 15 in the FIR filter 16, and then converted from a digital signal to an analog signal by the D / A converter 17, and is appropriately output by the output amplifier 18. Amplified to the signal level and output to the drive control means 9.

  Next, in FIG. 5 and FIG. 6, a method for suppressing secondary noise reaching the listener 4 will be described. The primary noise radiated from the noise source 1 reaches the boundary surface 3 and becomes secondary vibration, and reaches the listener 4 as secondary noise and is recognized as noise. The vibration after interference with the vibration output from the means 6 is detected by the secondary vibration detecting means 7 and converted into a digital signal via the input amplifier 13 and the A / D converter 14.

  Here, in order to perform a suppression method equivalent to the vibration suppression method described in the first embodiment, the vibration to be suppressed is input to the FIR filter 16, and the input signal is input to the LMS algorithm 15 as shown in Equation 1. It is necessary to input the vibration after causing the vibration to be suppressed to interfere with the control vibration to be an error signal. However, since the secondary vibration detection means 7 can only detect the vibration after causing the control vibration to interfere, it is necessary to create on the signal the vibration that is to be suppressed from the vibration detected by the secondary vibration detection means 7. .

  FIG. 7 shows the vibration waveform a after interference between the vibration to be suppressed and the control vibration (FIG. 7A), the waveform b of the control vibration (FIG. 7B), and the waveform c of the vibration to be suppressed (FIG. 7C). ). From the principle of superposition of vibrations, waveform b + waveform c = waveform a. Therefore, in order to obtain waveform c from waveform a, it is necessary to take a difference between waveform a and waveform b. That is, it is possible to create a vibration to be suppressed from the difference between the vibration after interference detected by the secondary vibration detecting means 7 and the control vibration.

  FIG. 8 is a diagram illustrating a path in which the control signal output from the FIR filter 16 is vibrated and output from the vibration generating unit 6 and then detected by the secondary vibration detecting unit 7 and input to the signal processing unit 10. It is. A D / A converter 17, an output amplifier 18, a drive control means 9, a vibration path from the vibration generating means 6 to the secondary vibration detecting means 7, a secondary vibration detecting means 7, an input amplifier 13, and an A / D converter 14 are provided. It has passed. If the transfer characteristic of this path is H, the FIR filter 19 in FIG. 6 estimates the transfer characteristic H. By convolving the FIR filter 19 with the output signal of the FIR filter 16, the control vibration can be estimated as the waveform b detected by the secondary vibration detection means 7, and the waveform after interference detected by the secondary vibration detection means 7. By taking the difference from a, a waveform c to be suppressed is generated.

  The waveform c to be suppressed generated in this way is supplied to the LMS algorithm 15 and the FIR filter 16 as an input signal. The digital signal that has passed through the FIR filter 16 whose tap coefficient has been updated by the LMS algorithm 15 is converted into an analog signal by the D / A converter 17, amplified to an appropriate signal level by the output amplifier 18, and drive control means 9 to output control vibration from the vibration generating means 6 to the boundary surface 3.

  On the other hand, in the secondary vibration detecting means 7 arranged close to or in close contact with the boundary surface 3, the vibration generating means 6 is converted into the secondary vibration generated when the primary noise radiated from the noise source 1 reaches the boundary surface 3. The vibration after causing the vibration generated by the above to interfere is detected. Further, since the vibration detected by the secondary vibration detecting means 7 is input to the error signal of the LMS algorithm 15 described above, the tap coefficient of the FIR filter 16 is updated so that the vibration after the interference approaches zero. Will be. As a result, the secondary vibration at the boundary surface 3 can be suppressed by the control vibration that has passed through the FIR filter 16, and the secondary noise that reaches the listener 4 can be reduced.

  FIG. 10 is a diagram showing a further simplified configuration of the configuration of FIG. 5, and shows a case where the noise from the noise source 1 reaches the listener 4 directly. The boundary surface 3 does not exist, the object to be suppressed is not the secondary vibration but the original vibration, and the vibration generating means 6 and the original vibration detecting means 5 are both arranged close to or in close proximity to the noise source 1. The operation for suppressing the vibration is omitted in the description of FIGS. 5 and 6 because the secondary vibration detecting means 7 is equivalent to the original vibration detecting means 5 and the secondary vibration is replaced with the original vibration.

  The active vibration noise control described above is called a feedback control system. In the process in which vibration becomes noise and diffuses into the space, the secondary vibration noise control is performed at the stage of suppressing the secondary vibration that is the source of the secondary noise. Since the secondary vibration is suppressed using the secondary vibration detection result itself, a small vibration control system can be easily constructed, and the noise generated by the device can be effectively reduced. Moreover, even when the degree of association (coherence) between the original vibration and the secondary vibration is low, vibration control is possible, and secondary noise can be reduced.

  FIG. 9 is an explanatory diagram supplementing the basic configuration of an active vibration noise control apparatus according to Embodiment 2 of the present invention. Aside from the process in which primary noise is radiated from the noise source 1 and propagates through the space and reaches the boundary surface 3 to become secondary vibration, the original vibration propagates through the base surface 2 and reaches the boundary surface 3. The case where the secondary noise reaches the listener 4 based on the secondary vibration of the boundary surface 3 is shown together with the process of secondary vibration. The mechanism for reducing noise reaching the listener 4 is the same as described above, except that the energy of the original vibration reaches the boundary surface 3 through a plurality of paths.

  Incidentally, in FIGS. 5 and 9, the secondary vibration of the boundary surface 3 is described as a direction close to perpendicular to the boundary surface 3, but the vibration is not limited to this direction, and vibration in a direction horizontal to the boundary surface Needless to say, this is a complex vibration with the components. Further, the vibration generating means 6 and the secondary vibration detecting means 7 are illustrated for convenience so that they are separated from each other. However, the present invention is not limited to this form. It doesn't matter.

  As a specific example of the secondary vibration detecting means 7, there can be considered a method in which an acceleration sensor is closely attached to a detection target in order to detect vibration, or a condenser microphone is in close proximity or in close contact. As a specific example of the vibration generating means 6, a configuration using a material that converts an electrical signal into mechanical vibration, such as an electric actuator, a piezoelectric actuator, or a giant magnetostrictive actuator, can be considered.

  On the other hand, in the present embodiment, the FIR filter 16 and the LMS algorithm 15 are used in the signal processing means 10, but any adaptive signal processing circuit that brings the vibration detected by the secondary vibration detection means 7 close to zero can be used. Alternatively, a filtered-X algorithm that is generally used in the automatic mute method may be used. Further, the signal processing means 10 may be configured to generate the control sound by a fixed tap coefficient instead of the adaptive signal processing. Further, the signal processing means 10 may be an analog signal processing circuit instead of digital signal processing.

  FIG. 11 is a diagram showing another application example of the active vibration noise control apparatus according to the second embodiment of the present invention. That is, when the boundary surface 3 is a window or a thin wall of a building, for example, which separates the outdoor from the indoor, and primary noise from various outdoor noise sources such as airplanes, automobiles, factories, etc. arrives, the boundary surface 3 Although the secondary noise reaches the indoor listener 4 through the secondary vibration, the indoor noise can also be reduced by suppressing the vibration of the boundary surface 3 as described with reference to FIG.

  According to the second embodiment of the present invention, the active vibration noise control apparatus includes the secondary vibration detecting means 7 for detecting the vibration of the boundary surface 3, and the boundary surface 3 is caused by the vibration of the noise source 1. Vibration generating means 6 installed on the boundary surface 3 between the first space in which the primary noise propagates and the second space in which the secondary noise propagates through the secondary vibration of the boundary surface 3; From the detection result in the next vibration detection means 7, a signal processing means 10 for generating a cancellation vibration signal, and a drive control means 9 for causing the vibration generation means 6 to generate a cancellation vibration corresponding to the vibration of the boundary surface 3 in response to the cancellation vibration signal. In the process in which the vibration of the noise source 1 becomes noise and diffuses into the first space and the second space, the secondary vibration that becomes the root of the noise is suppressed at the boundary surface 3. Widening noise It can be effectively reduced in the frequency range.

  DESCRIPTION OF SYMBOLS 1 Noise source 2 Base surface 3 Boundary surface 4 Listener 5 Original vibration detection means 6 Vibration generation means 7 Secondary vibration detection means 8, 10 Signal processing means 9 Drive control means 11, 13 Input Amplifier, 12, 14 A / D converter, 15 LMS algorithm, 16, 19 FIR filter, 17 D / A converter, 18 output amplifier.

Claims (7)

A secondary vibration detecting means for detecting the vibration of the boundary surface;
The boundary surface is installed between a first space in which primary noise due to vibration of a noise source propagates and a second space in which secondary noise propagates through secondary vibration of the boundary surface,
Vibration generating means installed on the boundary surface;
Signal processing means for generating a cancellation vibration signal from the detection result in the secondary vibration detection means,
Drive control means for causing the vibration generating means to generate a canceling vibration corresponding to the vibration of the boundary surface corresponding to the canceling vibration signal;
Active vibration noise control device. The secondary vibration detection means also detects the secondary vibration that has propagated solidly through the installation surface where the noise source is installed from the noise source to the boundary surface.
The active vibration noise control apparatus according to claim 1. An original vibration detecting means for detecting vibration of the noise source;
The signal processing means generates the cancellation vibration signal from detection results in the original vibration detection means and the secondary vibration detection means.
The active vibration noise control apparatus according to claim 1 or 2. The original vibration detection means is installed in the noise source.
The active vibration noise control apparatus according to claim 3. The original vibration detection means is installed on an installation surface on which the noise source is installed.
The active vibration noise control apparatus according to claim 3. The vibration generating means is an actuator.
The active vibration noise control apparatus according to claim 1. The original vibration detection means and the secondary vibration detection means are an acceleration sensor or a microphone.
The active vibration noise control apparatus according to claim 3.

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