JP4031875B2 - Active vibration and noise suppression device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an active vibration noise suppression device that suppresses vibration noise generated in synchronization with the rotational speed of an engine output shaft of a vehicle.
[0002]
[Prior art]
In a conventional active vibration noise suppression device that suppresses vibration noise generated in synchronization with the rotational speed of the engine output shaft of a vehicle (hereinafter, the active vibration noise suppression device is also referred to as “ANC”), an engine pulse is used as a reference signal. The feedforward adaptive control is performed to reduce the vibration noise by generating the secondary vibration noise for canceling the vibration noise to be suppressed.
[0003]
As shown in FIG. 7, the conventional ANC based on this feedforward adaptive control uses a signal synchronized with the ignition signal as an engine pulse and supplies the engine pulse as a reference signal to the adaptive filter 61, while an error signal (secondary vibration noise). An error signal based on the difference between the secondary vibration noise generated from the generator 63 and the vibration noise based on the engine pulse) and the engine pulse signal as the reference signal are supplied to the adaptive control algorithm computing unit 62, and the adaptive control algorithm An adaptive filter coefficient of the adaptive filter 61 is obtained by an arithmetic unit 62 based on an adaptive control algorithm such as an LMS algorithm, and the obtained adaptive filter coefficient is adapted to be set in the adaptive filter 61. Multiply by adaptive filter coefficient Brute adapt the output from the filter 61 is supplied to the secondary vibratory noise generator 63, to generate a secondary vibration noise at the secondary vibration noise generator 63, thereby suppressing the vibration noise based on the engine pulses.
[0004]
There is also known an active vibration noise suppression device 4A shown in FIG. 8 that uses an adaptive notch filter for ANC by this conventional feedforward adaptive control.
[0005]
As shown in FIG. 8, the active vibration noise suppression device 4A supplies the engine pulse to the waveform shaper 5 that removes noise superimposed on the engine pulse and shapes the noise-removed engine pulse. The engine pulse from which noise has been removed and shaped by the waveform shaper 5 is supplied to the cosine wave generator 6 and the sine wave generator 7 to generate a cosine wave signal synchronized with the engine pulse from the cosine wave generator 6. A sine wave signal synchronized with the engine pulse is generated from the sine wave generator 7. The sine wave generator 7 may be a delay device that generates a sine wave signal by delaying the output of the cosine wave generator 6 by π / 2 radians.
[0006]
A coefficient multiplier 9 and a sine wave signal for multiplying the cosine wave signal and the adaptive notch filter coefficient W0 by using the generated cosine wave signal from the cosine wave generator 6 and the generated sine wave signal from the sine wave generator 7 as reference signals. And an adaptive notch filter 8 having a coefficient multiplier 10 for multiplying the adaptive notch filter coefficient W1 and an adder 11 for adding the output of the coefficient multiplier 9 and the output of the coefficient multiplier 10.
[0007]
On the other hand, a cosine wave signal is supplied to a transfer element 21 having a notch frequency transfer characteristic C0 that is calculated from the engine output shaft speed, and a notch frequency transfer characteristic C1 that is calculated from the engine output shaft speed is obtained. A sine wave signal is supplied to the transmission element 22 having the signal, the output from the transmission element 21 and the output from the transmission element 22 are added by an adder 23, and the addition output signal r0 is used as an addition output signal r0 and an error signal e. Are supplied to the adaptive control algorithm computing unit 24A, the adaptive notch filter coefficient W0 is obtained based on an adaptive control algorithm, for example, the LMS algorithm, and is set as the adaptive notch filter coefficient W0 of the adaptive notch filter 8.
[0008]
Similarly, a sine wave signal is supplied to the transfer element 25 based on the transfer characteristic C0 of the notch frequency to be mute determined from the rotation speed of the engine output shaft, and the transfer characteristic of the mute notch frequency calculated from the rotation speed of the engine output shaft ( The cosine wave signal is supplied to the transmission element 26 having the transmission characteristic (−C1) with the polarity of C1) inverted, and the output from the transmission element 25 and the output from the transmission element 26 are added by the adder 27, and the addition is performed. Assuming that the output signal is r1, the addition output signal r1 and the error signal e are supplied to the adaptive control algorithm calculator 28A, the adaptive notch filter coefficient W1 is obtained based on the adaptive control algorithm, for example, the LMS algorithm, and the adaptive notch filter 8 The adaptive notch filter coefficient is W1.
[0009]
The output from the adaptive notch filter 8 is supplied to the secondary vibration noise generator 3 to generate secondary vibration noise in the secondary vibration noise generator 3 to cancel the vibration noise based on the engine pulse.
[0010]
Here, the notch frequency corresponds to the frequency of the engine pulse, which is a frequency for suppressing vibration noise.
[0011]
[Problems to be solved by the invention]
The active vibration noise suppression device that suppresses vibration noise using the conventional feedforward adaptive control described above is excellent in convergence.
[0012]
The adaptive notch filter coefficients W0 (n + 1) and W1 (n + 1) at the next sampling after the sampling period has elapsed from the sampling timing of the adaptive notch filter coefficients W0 (n) and W1 (n) are expressed by the following equations (1) and (1). ') As shown in the equation.
[0013]
W0 (n + 1) = W0 (n) −μ ′ · e (n) · r0 (n) (1)
W1 (n + 1) = W1 (n) −μ ′ · e (n) · r1 (n) (1 ′)
Here, W0 (n + 1) and W1 (n + 1) indicate the updated adaptive notch filter coefficients, and W0 (n) and W1 (n) indicate the adaptive notch filter coefficients immediately before the update. Further, e (n) indicates an error signal immediately before update, r0 (n) and r1 (n) indicate addition output signals immediately before update, and μ ′ indicates a step size parameter. Further, μ ′ · e (n) · r0 (n) and μ ′ · e (n) · r1 (n) indicate the update amount of the adaptive notch filter coefficient.
[0014]
However, in the case of applying the conventional active vibration noise suppression device to the vehicle interior vibration noise suppression, the intake / exhaust pipe vibration noise suppression, the engine mount vibration noise suppression, etc., for example, the vehicle interior vibration noise suppression As shown in FIG. 9 (a), the engine output shaft speed vs. time characteristics during sudden acceleration and the vehicle interior vibration noise amplitude level vs. time characteristics shown in FIG. 9 (b). The level of the error signal changes as the engine output shaft speed changes.
[0015]
For this reason, the update amounts μ ′ · e (n) · r0 (n) and μ ′ · e (n) · r1 (n) of the adaptive notch filter coefficient change with the rotational speed of the engine output shaft.
[0016]
Therefore, if the step size parameter μ ′ is set to a value that will obtain a vibration and noise suppression effect in the low engine speed range of the engine output shaft, the update amount of the adaptive notch filter coefficient will diverge or increase in the high engine speed range. If the value is set so as to obtain a vibration noise suppression effect, it takes time to suppress the vibration of the adaptive notch filter in a low rotational speed range, and there is a problem that the vibration noise suppression effect cannot be obtained.
[0017]
In addition, the step size parameter μ ′ prepared in advance for the above is switched based on the number of rotations of the engine output shaft, or the output suppression of the adaptive control algorithm computing unit is introduced. In addition to the problem that the number of items to be set increases and man-hours are required for setting, there arises a problem that it becomes difficult to obtain a good vibration noise suppression effect.
[0018]
An object of the present invention is to provide an active vibration noise suppression device capable of suppressing vibration noise regardless of changes in vibration noise sources.
[0019]
[Means for Solving the Problems]
The active vibration noise suppression apparatus according to claim 1 according to the present invention is an adaptive vibration noise suppression apparatus that adapts the adaptive notch filter coefficient of the adaptive notch filter and cancels the vibration noise based on the output of the adaptive notch filter. the update amount of filter coefficients, and changes based on the step-size parameter that is proportional to 1 in amplitude of the output of the adaptive notch filter of the adaptive notch filter coefficient updating immediately before.
[0020]
Active vibration noise suppression apparatus according claim 1, wherein in the present invention, the update amount of the adaptive notch filter coefficients of the adaptive notch filter, the step size parameter that is proportional to 1 in amplitude of the output of the adaptive notch filter in the update immediately before Therefore, it does not change suddenly regardless of the change of the vibration noise source, the amount of renewal of the adaptive notch filter coefficient does not diverge or it takes time to suppress the vibration noise, and the vibration noise is canceled out. Done effectively.
[0021]
The active vibration noise suppression apparatus according to claim 2 according to the present invention is an active vibration noise suppression apparatus for canceling vibration noise based on an output of the adaptive notch filter by adapting an adaptive notch filter coefficient of the adaptive notch filter. the update amount of filter coefficients, and changes based on the step-size parameter that is proportional to 1 divided by the square power of the amplitude of the output of the adaptive notch filter of the adaptive notch filter coefficient updating immediately before.
[0022]
Step active vibration noise control apparatus according to claim 2 wherein according to the present invention, the update amount of the adaptive notch filter coefficients of the adaptive notch filter, you proportional to 1 divided by the square power of the amplitude of the output of the adaptive notch filter in the update immediately before Because it is changed based on the size parameter, it does not change suddenly regardless of changes in the vibration noise source, and the amount of update of the adaptive notch filter coefficient does not diverge or it takes time to suppress the vibration noise. Is effectively cancelled.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an active vibration noise suppression device according to the present invention will be described with reference to embodiments.
[0024]
FIG. 1 is a block diagram showing a configuration of an active vibration noise suppression device 4 according to an embodiment of the present invention.
[0025]
In the active vibration and noise suppression device 4 according to the embodiment of the present invention shown in FIG. 1, the same components as those in the conventional active vibration and noise suppression device 4A shown in FIG. The adaptive control algorithm calculator of the active vibration noise suppression device 4 is different from the adaptive control algorithm calculator of the active vibration noise suppression device 4A.
[0026]
In the active vibration noise suppressing apparatus 4 according to the embodiment of the present invention, an engine pulse obtained from an engine that is a vibration noise source, for example, an engine pulse obtained from a signal synchronized with an ignition signal, is generated by superimposing noise superimposed on the engine pulse. And is supplied to a waveform shaper 5 that shapes the engine pulse. The engine pulse from which noise has been removed and shaped by the waveform shaper 5 is supplied to the cosine wave generator 6 and the sine wave generator 7 to generate a cosine wave signal synchronized with the engine pulse from the cosine wave generator 6. A sine wave signal synchronized with the engine pulse is generated from the sine wave generator 7.
[0027]
The sine wave generator 7 may be a delay device that generates a sine wave by delaying the output of the cosine wave generator 6 by π / 2 radians.
[0028]
A coefficient multiplier 9 and a sine wave signal for multiplying the cosine wave signal and the adaptive notch filter coefficient W0 by using the generated cosine wave signal from the cosine wave generator 6 and the generated sine wave signal from the sine wave generator 7 as reference signals. And an adaptive notch filter 8 having a coefficient multiplier 10 for multiplying the adaptive notch filter coefficient W1 and an adder 11 for adding the output of the coefficient multiplier 9 and the output of the coefficient multiplier 10.
[0029]
On the other hand, a cosine wave signal is supplied to a transfer element 21 having a notch frequency transfer characteristic C0 that is calculated from the engine output shaft speed, and a notch frequency transfer characteristic C1 that is calculated from the engine output shaft speed is obtained. A sine wave signal is supplied to the transmission element 22 having the signal, the output from the transmission element 21 and the output from the transmission element 22 are added by an adder 23, and the addition output signal r0 is used as an addition output signal r0 and an error signal e. Are supplied to the adaptive control algorithm computing unit 24, and an adaptive notch filter coefficient W0 is obtained based on an adaptive control algorithm, for example, an LMS algorithm.
[0030]
Similarly, a sine wave signal is supplied to the transfer element 25 based on the transfer characteristic C0 of the notch frequency to be mute determined from the rotation speed of the engine output shaft, and the transfer characteristic of the mute notch frequency calculated from the rotation speed of the engine output shaft ( The cosine wave signal is supplied to the transmission element 26 having the transmission characteristic (−C1) with the polarity of C1) inverted, and the output from the transmission element 25 and the output from the transmission element 26 are added by the adder 27, and the addition is performed. Assuming that the output signal is r1, the addition output signal r1 and the error signal e are supplied to the adaptive control algorithm calculator 28, and the adaptive notch filter coefficient W1 is obtained based on the adaptive control algorithm, for example, the LMS algorithm.
[0031]
Further, the adaptive control algorithm computing unit 24 receives the adaptive notch filter coefficient W1 (n) from the adaptive control algorithm computing unit 28, and the adaptive control algorithm computing unit 28 receives the adaptive notch filter coefficient from the adaptive control algorithm computing unit 24. When W0 (n) is input, the step size parameter μ is set for the adaptive notch filter coefficients W0 (n) and W1 (n) immediately before the update, as shown in the following equation (2). The updated adaptive notch filter coefficients W0 (n + 1) and W1 (n + 1) are obtained by the set step size parameter μ, and the updated notch filter coefficients W0 (n) and W1 (n) immediately after the update are updated. Adaptive notch filter coefficients W0 (n + 1) and W1 (n + 1) are respectively supplied to the coefficient multipliers 9 and 10 of the adaptive notch filter 8. Is done.
[0032]
μ = α / A (2)
Here, α indicates a positive constant, A corresponds to the amplitude of the output from the adaptive notch filter 8 immediately before the update or the square of the amplitude,
A = √ {(W0 (n)) ² + (W1 (n)) ² }
Or, A = (W0 (n)) ² + (W1 (n)) ²
It is.
[0033]
The cosine wave signal output from the cosine wave generator 6 and the sine wave signal output from the sine wave generator 7 are both equal in amplitude and orthogonal to each other, and the adaptive notch filter coefficient for the cosine wave signal is W0. Since the adaptive notch filter coefficient for the sine wave signal is W1, A corresponds to the amplitude of the output from the adaptive notch filter 8 immediately before the adaptive notch filter coefficient update of the adaptive notch filter 8 or the square of the amplitude. Will be easily understood.
[0034]
Therefore, the updated adaptive notch filter coefficients W0 (n + 1) and W1 (n + 1) are as shown in the following equations (3) and (3 ').
[0035]
W0 (n + 1) = W0 (n)-[mu] .e (n) .r0 (n) (3 ')
W1 (n + 1) = W1 (n) −μ · e (n) · r1 (n) (3)
The output from the adaptive notch filter 8 is supplied to the secondary vibration noise generator 3, and the secondary vibration noise generator 3 generates secondary vibration noise to cancel the vibration noise based on the engine pulse.
[0036]
Here, the notch frequency corresponds to the frequency of the engine pulse, which is a frequency for suppressing vibration noise.
[0037]
As described above, since the step size parameter μ is proportional to (1 / the amplitude of the output of the adder 11 immediately before the update), the update amount μ · e (n) · r0 (n) and μ · e of the adaptive notch filter coefficient are updated. (N) and r1 (n) do not change suddenly regardless of changes in the engine output shaft speed, and the amount of renewal of the adaptive notch filter coefficient does not diverge and it does not take time to suppress vibration noise. The vibration noise is effectively canceled out.
[0038]
FIG. 2 is a characteristic diagram showing vibration noise suppression by the active vibration noise suppression apparatus according to the embodiment of the present invention.
[0039]
The solid line in FIG. 2 indicates the sound pressure level (SPL) indicating the vibration noise suppression by the active vibration noise suppression device 4 when the adaptive notch filter coefficient updated with the update amount according to the equations (3) and (3 ′) is used. The rotational speed characteristic of the engine output shaft is indicated by a broken line in FIG. 2 when the vibration suppression control is not performed.
[0040]
On the other hand, FIG. 3 is a characteristic diagram showing vibration noise suppression by a conventional active vibration noise suppression apparatus.
[0041]
The solid line in FIG. 3 is the sound pressure level (SPL) vs. engine output shaft speed characteristics indicating vibration noise suppression when the conventional active vibration noise suppression device 4A shown in FIG. 8 is used, and the broken line in FIG. 3 is vibration suppression. This is a characteristic when control is not performed.
[0042]
As is apparent from a comparison between FIG. 2 and FIG. 3, the vibration and noise suppression effect is more remarkable in the case of FIG. 2, and particularly remarkable in the range of the engine output shaft speed of 1000 to 3000 RPM.
[0043]
【Example】
Next, an embodiment of the active vibration and noise suppression device according to the present invention will be described.
[0044]
FIG. 4 is a block diagram showing the configuration of the first embodiment of the active vibration noise suppressing apparatus according to the present invention.
[0045]
The first embodiment shows a case in which vehicle interior vibration noise due to engine vibration is suppressed.
[0046]
In the first embodiment, an engine pulse based on the rotation of the in-vehicle engine output shaft is sent to the active vibration noise suppressing device 4 according to the embodiment of the present invention, and the output from the active vibration noise suppressing device 4, that is, adaptation is applied. The output of the notch filter 8 is generated through the mixer 30 as a secondary vibration noise provided behind the backrest of the speaker 31 and the rear seat, which also acts as a secondary vibration noise generator provided in the lower part of the driver's seat of the vehicle. It supplies to the speaker 32 which acts also as a device, and it is configured to drive the speakers 31 and 32 based on the output of the adaptive notch filter 8.
[0047]
Here, the mixer 30 shares the speakers 31 and 32 with the speaker for reproducing the audio signal from the audio unit 34 which is an audio device such as a radio receiver and a magnetic tape reproducing device provided in the vehicle. Is provided.
[0048]
In the first embodiment configured as described above, the vibration noise generated in the passenger compartment based on the engine pulse or the crankshaft rotation pulse when the vehicle is driven is driven by the output of the active vibration noise suppression device 4. Canceled by the output vibration noise from the speakers 31 and 32.
[0049]
FIG. 5 is a block diagram showing the configuration of the second embodiment of the active vibration noise suppressing apparatus according to the present invention.
[0050]
The second embodiment shows a case where vibration noise of the intake pipe and exhaust pipe due to engine vibration is suppressed.
[0051]
In the second embodiment, an engine pulse based on the rotation of the output shaft of the in-vehicle engine 41 is supplied to the active vibration noise suppression device 4 according to one embodiment of the present invention, and the output from the adaptive notch filter 8, that is, the active The output from the vibration noise suppression device 4 is supplied to an actuator 45 for canceling vibration of the intake pipe 42 of the in-vehicle engine 41 and an actuator 46 for canceling vibration of the exhaust pipe 43 of the in-vehicle engine 41 to suppress active vibration noise. Actuators 45 and 46 are driven by the output from device 4.
[0052]
In the second embodiment, the vibration noise of the intake pipe 42 and the vibration noise of the exhaust pipe 43 based on the vibration of the in-vehicle engine 41 are suppressed by driving the actuators 45 and 46 by the output from the active vibration noise suppression device 4. .
[0053]
FIG. 6 is a block diagram showing the configuration of the third embodiment of the active vibration and noise suppression apparatus according to the present invention.
[0054]
The third embodiment shows a case where the vibration of the engine itself is suppressed.
[0055]
In the third embodiment, the engine pulse of the in-vehicle engine 41 is supplied to the active vibration noise suppression device 4 according to the embodiment of the present invention, and the output from the adaptive notch filter 8, that is, the active vibration noise suppression device 4 The output drives the active engine mounts 50A and 50B for canceling the vibration of the in-vehicle engine 41.
[0056]
In the third embodiment, the active engine mounts 50 </ b> A and 50 </ b> B are driven by the output of the active vibration noise suppression device 4 to suppress the vibration of the in-vehicle engine 41 and cancel the engine vibration noise based on the vibration of the in-vehicle engine 41. It is.
[0057]
【The invention's effect】
As described above, according to the active vibration noise control apparatus according to the present invention, the update amount of the adaptive notch filter coefficients of the adaptive notch filter, the output of the adaptive notch filter immediately before the update of the amplitude component 1 or updating the immediately preceding, because change based on the step-size parameter proportional to 1 divided by the square power of the amplitude of the output of the adaptive notch filter, capable of accommodating a change in vibration noise source, it is possible to perform vibration noise suppressing effectively.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an active vibration noise suppression apparatus according to an embodiment of the present invention.
FIG. 2 is a characteristic diagram showing vibration noise suppression by the active vibration noise suppression apparatus according to the embodiment of the present invention.
FIG. 3 is a characteristic diagram showing vibration noise suppression by a conventional active vibration noise suppression apparatus for comparison with the active vibration noise suppression apparatus according to the embodiment of the present invention.
FIG. 4 is a block diagram showing the configuration of the first embodiment of the active vibration noise suppression apparatus according to the present invention;
FIG. 5 is a block diagram showing a configuration of a second embodiment of the active vibration noise suppression apparatus according to the present invention;
FIG. 6 is a block diagram showing a configuration of a third embodiment of the active vibration noise suppression apparatus according to the present invention;
FIG. 7 is a block diagram showing a configuration of a conventional active vibration noise suppression device.
FIG. 8 is a block diagram showing a configuration of another conventional active vibration noise suppression device.
FIG. 9 is a characteristic diagram showing vibration noise suppression for explaining the operation of the active vibration noise suppression device shown in FIG. 8;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 3 ... Secondary vibration noise generator 4 ... Active vibration noise suppression apparatus 5 ... Waveform shaper 6 ... Cosine wave generator 7 ... Sine wave generator 8 ... Adaptive notch filter 9, 10 ... Coefficient multiplier 11, 23, 27 ... Adders 21, 22, 25, 26 ... transfer elements 24, 28 ... adaptive control algorithm calculator 30 ... mixer 31, 32 ... speaker 41 ... in-vehicle engine 42 ... intake pipe 43 ... exhaust pipe 45, 46 ... actuators 50A, 50B ... Active engine mount

Claims (2)

In an active vibration noise suppressor that adapts the adaptive notch filter coefficient of the adaptive notch filter and cancels the vibration noise based on the output of the adaptive notch filter, the amount of update of the adaptive notch filter coefficient is the adaptive notch immediately before the update of the adaptive notch filter coefficient. active vibration noise suppression apparatus and changes based on the step-size parameter that is proportional to 1 in amplitude of the output of the filter. In an active vibration noise suppressor that adapts the adaptive notch filter coefficient of the adaptive notch filter and cancels the vibration noise based on the output of the adaptive notch filter, the amount of update of the adaptive notch filter coefficient is the adaptive notch immediately before the update of the adaptive notch filter coefficient. active vibration noise suppression apparatus and changes based on the step-size parameter that is proportional to 1 divided by the square power of the amplitude of the output of the filter.

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