JP3328946B2 - Active uncomfortable wave control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active unpleasant wave control device for actively reducing noise or vibration unpleasant waves in a passenger compartment of an automobile or a cabin of an aircraft.

[0002]

2. Description of the Related Art Conventionally, as an active type unpleasant wave control device of this type, there is one shown in FIG. 15 of British Patent Publication No. 2149614, for example.

[0003] This conventional device is constituted by an adaptive signal processing device and is applied to a cabin of an aircraft or a closed space similar to this, and a loudspeaker 103 is provided in a closed space 101.
a, 103b, 103c and microphone 105a,
The loudspeakers 103a, 103b, and 103d generate control sounds (control waves) that interfere with noise (unpleasant waves), and the microphones 105a, 105b, 105c, and 105d generate residual signals (residual signals). Unpleasant waves). These loudspeakers 103a, 103b, 103
c, microphones 105a, 105b, 105c, 10
5d is connected to the signal processor 107. The signal processor 107 is connected to the microphone 105a, 1 and the fundamental frequency of the noise source (unpleasant wave source) measured by the fundamental frequency measuring means.
It receives the input signals from the loudspeakers 05b, 105c, and 105d and outputs drive signals to the loudspeakers 103a, 103b, and 103c so as to minimize the sound pressure level in the closed space 101.

FIG. 16 is a block diagram conceptually showing a case in which the active unpleasant wave control device is applied as an active noise control device for an automobile.

It is assumed that one loudspeaker 103 and one microphone 105 are provided for the sake of simplicity.

Now, let G be the transfer function of the vehicle transfer system from the noise source (unpleasant wave source) to the microphone 105, C be the transfer function from the loudspeaker 103 to the microphone 105, and X be the sound source information signal generated by the noise source. When _p, the signal E as a residual discomfort waves observed at the microphone 105 becomes _{E = X p · G + X} p · W · C. Here, W is a transfer function required for silencing. E = 0 when the noise (unpleasant wave) is completely canceled at the target point (the position of the microphone 105). At this time, W becomes W = −G · C ⁻¹ . That is, in order to cancel the noise (primary sound) transmitted into the vehicle cabin of the vehicle by the control sound (secondary sound) output from the loudspeaker 103, the transfer function G of the vehicle transmission system is W · C needs to be an equivalent transfer function. Then, W at which the microphone detection signal E is minimized is obtained, and the filter coefficient W of the adaptive digital filter in the signal processor 107 is adaptively updated based on this W.

As a method of obtaining the filter coefficient W so as to minimize the microphone detection signal E, one of the steepest descent methods, L
MS algorithm (Least Mean Square)
e) etc. are used.

[0008]

There are various types of vehicle noise such as engine noise, vibration, engine noise based on suspension vibration, road noise, and the like.
Here, in the case of engine noise, since the signal is a simple sine wave, the filter coefficient W of the adaptive digital filter in the signal processor 107 need only represent the phase and amplitude of the signal. Therefore, even when the calculation load of the signal processor 107 is small and the frequency sequentially changes due to a change in the engine speed, the filter coefficient W is updated quickly and appropriately.

[0009] However, if the noise is road noise due to suspension vibration, the signal becomes extremely complicated and signal processing becomes difficult.

That is, in the case of road noise, the impulse response expressing the transfer characteristic of G is a signal having reverberation characteristics as shown in FIG. 17, and in digital signal processing, convolution of this impulse response function is performed. Therefore, the filter coefficient W needs to have the same reverberation characteristic as G. Therefore, the digital filter that accurately represents W has a very large number of filter coefficients, and it is necessary to update these filter coefficients sequentially in time series during filtering.

Here, if the transfer function G of the vehicle transmission system does not change during traveling, the updating operation of the filter coefficient W becomes unnecessary once the signal processor 107 outputs the signal of the target waveform. However, in reality, due to the bending of the suspension and the non-linearity of the intervening bushes, etc., FIG.
G changes under various conditions as in (a) and (b), and it is necessary to update the filter coefficient W accordingly.

Therefore, the number of updates of the filter coefficient W becomes enormous, and the calculation load of the signal processor 107 becomes extremely large.

In this case, if the signal processor 107 has a sufficient capacity, even if there is a sudden change in G due to a change in the vehicle body posture due to sudden acceleration, sudden braking, or the like, various signals are input from one to the next. The calculation can be performed at high speed with respect to the suspension vibration, and the update of the filter coefficient W can be sufficiently followed. On the other hand, if the capacity of the signal processor 107 is not sufficient, the update of the filter coefficient W sufficiently follows the suspension vibration input from one to the next when there is a sudden change in G. Can not.

For this reason, when a random signal is inputted one after another as in the noise reduction of road noise,
In order to sufficiently update the update of all the filter coefficients in response to the rapid change of G, the signal processor 107 having an extremely large capacity is required, and there is a problem that the apparatus becomes extremely large.

It is an object of the present invention to provide an active-type unpleasant wave control device which does not impair the followability while reducing the size of the device.

[0016]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a control wave source for generating a control wave for causing interference with noise or vibration unpleasant waves to reduce unpleasant waves at an evaluation point. Means for detecting a residual wave at a predetermined position after the interference, means for detecting a signal relating to an unpleasant wave generation state of an unpleasant wave source, and filtering and controlling the detection signal of the unpleasant wave generation state by a predetermined filter coefficient. An adaptive digital filter for outputting a signal for driving the wave source, and an output of the residual unpleasant wave detecting means using a predetermined control algorithm based on an output signal of the residual unpleasant wave detecting means and an output signal of the unpleasant wave occurrence state detecting means. An adaptive controller for successively updating the filter coefficients of the adaptive digital filter so as to reduce the signal, and detecting means for detecting a running state of the vehicle.
Means for predicting a change state of a transfer function of a rating point from the discomfort wave source based on output signals, and means for the predicted change in state determines whether above a predetermined threshold value, the state changes the predetermined threshold value And a means for stopping the adaptive operation of the adaptive controller upon receiving a signal output from the determination means when it is determined that the control wave exceeds the control wave, or a means for stopping the control wave.

According to a second aspect of the present invention, there is provided a control wave source for generating a control wave for causing interference with noise or vibration unpleasant waves to reduce unpleasant waves at an evaluation point, and detecting a residual unpleasant wave at a predetermined position after the interference. Means, means for detecting a signal related to the unpleasant wave occurrence state of the unpleasant wave source, and an adaptive digital filter that outputs a signal for driving the control wave source by filtering the detection signal of the unpleasant wave occurrence state with a predetermined filter coefficient,
A filter coefficient of the adaptive digital filter so as to reduce an output signal of the residual unpleasant wave detecting means using a predetermined control algorithm based on an output signal of the residual unpleasant wave detecting means and an output signal of the unpleasant wave occurrence state detecting means. And an adaptive controller for sequentially updating the vehicle, and detecting the traveling state of the vehicle.
Means for predicting a change state of the transfer function from the unpleasant wave source to the evaluation point based on the detection signal of the means, means for previously storing a plurality of correction values corresponding to the change state of the transfer function, Judgment that the change state exceeds a predetermined threshold
Means for selecting the correction value and correcting the drive signal to the control wave source when the correction is made.

According to a third aspect of the present invention, there is provided the active unpleasant wave control device according to the first or second aspect, wherein the change state predicting means of the transfer function predicts the change state of the posture of the vehicle body. It is based on a signal.

According to a fourth aspect of the present invention, there is provided the active type unpleasant wave control device according to the third aspect, wherein the posture change state detecting means of the vehicle body is provided at a predetermined position of the vehicle body and detects the acceleration of the vehicle body. It is a sensor.

According to a fifth aspect of the present invention, there is provided the active discomfort wave control device according to the third aspect, wherein the attitude change state detecting means of the vehicle body is a throttle opening sensor for detecting a throttle opening amount of an engine. It is characterized by.

According to a sixth aspect of the present invention, there is provided the active unpleasant wave control device according to the third aspect, wherein the posture change state detecting means of the vehicle body is a brake sensor for detecting a brake depression amount. I do.

According to a seventh aspect of the present invention, there is provided the active unpleasant wave control device according to the third aspect, wherein the posture change state detecting means of the vehicle body is a steering angle and angular velocity sensor for detecting a steering angle and an angular velocity of the steering. There is a feature.

[0023]

According to the first aspect of the present invention, the unpleasant wave generation state detecting means detects a signal relating to the unpleasant wave generation state of the unpleasant wave source, and the adaptive digital filter filters the detection signal of the unpleasant wave generation state by a predetermined filter coefficient. A signal for driving the control wave source is output. As a result, the control wave source can generate a control wave that interferes with the unpleasant wave, thereby reducing the unpleasant wave at the evaluation point.

At this time, the adaptive controller reduces the output signal of the residual unpleasant wave detection means using a predetermined control algorithm based on the output signal of the residual unpleasant wave detection means and the output signal of the unpleasant wave generation state detection means. Thus, the filter coefficients of the adaptive digital filter are sequentially updated.

The predicting means predicts a change state of the transfer function from the source of the unpleasant wave to the evaluation point, and the determining means determines whether or not the predicted change state exceeds a predetermined state. The stop means receives the signal output from the determination means, stops the adaptive operation of the adaptive controller, and stops the control.

According to the second aspect of the present invention, the storage means stores in advance a plurality of correction values according to the change state of the transfer function.
The correction means selects a correction value according to the change state predicted by the prediction means, and corrects the drive signal of the control wave source output by the adaptive digital filter.

According to the third aspect of the invention, the change state of the transfer function from the source of the unpleasant wave to the evaluation point can be predicted by the posture change state of the vehicle body detected by the posture change state detecting means.

According to the fourth aspect of the present invention, the posture change state of the vehicle body can be detected based on the vehicle body acceleration detected by the vehicle body acceleration sensor.

According to the fifth aspect of the present invention, the posture change state of the vehicle body can be detected based on the throttle opening amount of the engine detected by the throttle opening sensor.

According to the sixth aspect of the invention, the posture change state of the vehicle body can be detected based on the amount of depression of the brake detected by the brake sensor.

According to the seventh aspect of the present invention, the posture change state of the vehicle body can be detected based on the steering angle and the acceleration detected by the steering angle and acceleration sensor.

[0032]

Embodiments of the present invention will be described below.

The description will be made by taking the interior space of the vehicle as an example.

First Embodiment FIG. 1 is a schematic view showing a first embodiment of the present invention.

As shown in FIG. 1, the vehicle body 1 is supported by front wheels 2a, 2b and rear wheels 2c, 2d, and the front wheels 2a, 2b are rotationally driven by an engine 4 disposed at the front of the vehicle body 1, so-called front engine front wheels. It constitutes a driving car.

The noise unpleasant waves in the vehicle compartment are caused by, for example, suspension vibrations caused by unevenness of the road surface (unpleasant wave sources). The unpleasant wave generation state detecting means includes a suspension spindle for detecting the suspension vibrations. Suspension acceleration detectors 5a-
5d is used. The output signals from these suspension acceleration detectors 5a to 5d (road vibration signals input from the road surface to the suspension) are signals (acceleration signals x) correlated with vehicle interior noise.

A loudspeaker 7a, 7b, 7 is provided as a control wave source in a cabin 6 as an acoustic closed space in the vehicle body 1.
c and 7d are front seats S1, S2 and rear seat S3, respectively.
It is located on the door facing S4.

Further, microphones 8a to 8h are disposed at the headrest positions of the respective seats S1 to S4 as residual unpleasant wave detecting means.

The residual noise (residual unpleasant wave) in the passenger compartment 6 input to the microphones 8a to 8h is configured to output noise signals e _{1 to} e ₈ as electric signals corresponding to the sound pressure. I have.

The suspension acceleration detectors 5a-5
d and output signals of the microphones 8a to 8h are configured to be individually supplied to the controller 10. The drive signals y _{1 to} y ₄ output from the controller 10 are individually supplied to loudspeakers 7 a to ₇ d, and sound signals (control waves) are output from the speakers 7 a to 7 d into the vehicle interior 6. ing.

The controller 10 includes a first digital filter 12, a second digital filter (adaptive digital filter) 13, and a microprocessor (adaptive controller) 16, as shown in FIG. Then, the acceleration signal x input from the suspension acceleration detectors 5a to 5d is converted into a digital signal by the A / D converter 11, and is converted into a digital signal by the first digital filter 12 as a reference signal x.
And input to the adaptive digital filter 13.

The noise signals e _{1 to} e ₈ , which are the output signals of the microphones 8a to 8h, are output from the amplifiers 14a to 14a.
4h, and is A / D converted by A / D converters 15a to 15h.
2 is input to the microprocessor 16 together with the output signal.

Here, the first digital filter 12
Inputs the acceleration signal x and inputs the microphones 8a to 8
The reference signal r _lm (see equations (4) and (5) to be described later) that is filtered in accordance with the number of combinations of the transfer functions between h and the speakers 7a to 7d is generated.

The adaptive digital filter 13 functionally has a filter corresponding to the number of output channels to the speakers 7a to 7d, inputs an acceleration signal x, and sets a filter coefficient (described later) set at that time. (See equation (5)) to perform adaptive signal processing (filter processing) and output speaker drive signals y _{1 to} y ₄ .

The drive signals y _{1 to} y ₄ output from the adaptive digital filter 13 are converted into D / A converters 17a to 17
The D / A conversion is performed by d, and output to the loudspeakers 7a to 7d via the amplifiers 18a to 18d.

The microprocessor 16 generates the noise signals e _{1 to} e _{8 and the} filtered reference signal r _lm.
, And the filter coefficient is sequentially updated using an LMS algorithm, which is a kind of steepest descent method, so that the output signal of the adaptive digital filter 13 has a target signal waveform. Accordingly, the microprocessor 16 uses the predetermined control algorithm based on the output signal of the residual unpleasant wave detection means and the output signal of the unpleasant wave occurrence state detection means, and uses the microphones 8a to 8h as the residual unpleasant wave detection means.
Means for sequentially updating the filter coefficient W of the adaptive digital filter 13 so as to reduce the output signal of the adaptive digital filter 13.

On the other hand, in one embodiment of the present invention, as shown in FIG. 2, a vehicle body acceleration sensor 21, a judgment circuit 23, an adaptive stop switch 25, and a control sound stop switch 26 are provided.

The vehicle body acceleration sensor 21 constitutes a means for detecting a posture change state of the vehicle body 1, and detects a posture change state of the vehicle body 1 at the time of sudden acceleration, sudden braking, etc., and outputs it to the judgment circuit 23. Things. Then, when the posture of the vehicle body 1 changes, the transfer function G between the noise source and the microphones 8a to 8h changes due to the bending of the suspension or the nonlinearity of the intervening bushes, etc. That is, the change state of the transfer function G from the noise source to the microphones 8a to 8h can be predicted by determining the detection value of the vehicle body acceleration sensor 21 by the determination circuit 23.

Therefore, the vehicle body acceleration sensor 21 and the judgment circuit 23 constitute a means for estimating a change state of the transfer function.

The vehicle acceleration sensor 21 is shown in FIG.
It is provided as shown in FIG. FIG. 3 is a schematic block diagram of the configuration of the vehicle body 1 viewed from the side for easy understanding of the overall configuration. The numbers and arrangement of the loudspeakers, microphones, and suspension acceleration sensors are different. The same thing is representatively shown. The vehicle body acceleration sensor 21 detects the vehicle body 1
Are provided, for example, in an engine room or the like.

As shown in FIGS. 2 and 3, the judgment circuit 23 constitutes means for judging whether or not the predicted change state of the transfer function G exceeds a predetermined state. Sometimes, when the transfer function G changes greatly in a short time, a signal is output to the stop switches 25 and 26.

The adaptive stop switch 25 constitutes means for stopping the adaptive operation of the adaptive controller in response to the output signal from the decision circuit 23. The switch 16 turns off the microprocessor 16 and the adaptive digital filter 13 when the switch is turned off.
And to cut off the circuit between them.

The control sound stop switch 26 receives the output signal from the determination circuit 23 and cuts off the input of the adaptive filter, and stops the control sound by turning off the switch.

FIG. 4 is a simplified version of the adaptive digital filter 1 shown in FIG.
3 and microprocessor 16 and body acceleration sensor 2
1. Blocking of the relationship between the decision circuit 23 and the stop switches 25 and 26.

Here, the principle of noise reduction control of the controller 10 will be described using a general formula.

Now, the noise signal detected by the l-th microphone is e _l (n), and the residual noise detection signal detected by the l-th microphone when there is no control sound (secondary sound) from the loudspeakers 7a to 7d. the e _pl (n), J-th m th loudspeaker and l-th transfer function between microphone (FIR (finite impulse response) _{function) H lm (J = 0,1,2,} ..., I c -1) The filter coefficient corresponding to [I _c is a constant] is C _lmj , the reference signal is X (n), and the ith (i = 0, 1) of the adaptive filter which inputs the reference signal and drives the m-th loudspeaker .., I _k −1) where W _mi is the coefficient of [I _k is a constant],

(Equation 1) Holds. Here, each term with (n) is a sample value at sampling time n, M is the number of loudspeakers (four in this embodiment), and I _c is a filter expressed by an FIR digital filter. The number of taps (filter order) of the coefficient C _lm and I _k are the number of taps (filter order) of the filter coefficient W _mi of the adaptive filter.

[0057] In the above formula (1), of the right-hand side "ΣW _mi x (n-j
−i) ”(= y _m ) is the term of the adaptive digital filter 13.
_Represents the output when the reference signal x is input to the “、 C _lmj
Term _{{ΣW mi x (n-j} -i)} "is the signal energy input to the m-th speaker is output as the acoustic energy from these speakers, l-th through the transfer function C _lm in the passenger compartment 6 represents the signal when it reaches the microphone, further, the entire right side of the _{"Σ ΣC lmj {ΣW mi x (} n-j-i)} " is a reaching signal to the l-th microphone are summed for all the speakers Represents the sum of control sounds reaching the l-th microphone.

Next, the evaluation function (variable to be minimized) Je
To

(Equation 2) far. Here, L is the number of microphones (eight in this embodiment).

In this embodiment, the LMS algorithm is used to find the filter coefficient W _mi that minimizes the evaluation function Je. That is, the filter coefficient W _mi is obtained by partially differentiating the evaluation function Je with respect to each filter coefficient W _mi.
To update. Therefore, from equation (2),

(Equation 3) From the equation (1),

(Equation 4) If the right side of the equation (4) is r _lm (n−i), the rewrite equation of the filter coefficient is obtained by the following equation (5) including the weight coefficient γ _l .

[0060]

(Equation 5) Here, α is a convergence coefficient, which is related to the speed at which the filter converges optimally and the stability at that time. Although the convergence coefficient α is treated as one constant in this embodiment, a different convergence coefficient (α _mi ) may be used for each filter, or a coefficient obtained by incorporating the weight coefficient γ _l together. (Α _l ).

Next, the operation will be described with reference to the flowcharts of FIGS.

FIG. 5 is a flowchart for outputting the speaker drive signal, and FIG. 6 is a flowchart for updating the filter coefficients of the adaptive digital filter 13.

First, in FIG. 5, in step _S51 , an acceleration detection signal is input. That is, the acceleration detector 5a
The acceleration detection signal input from .about.5d is converted into a digital signal by the frequency-voltage conversion circuit 11, and is input to the adaptive digital filter 13 as the reference signal x. Next, in step _S52 , the reference signal x is filtered. That is, the adaptive digital filter 13
, A filter process is performed based on the filter coefficient (see the equation (5)) set at that time, and speaker drive signals y _{1 to} y ₄ are output. Next, step _S53
, The speaker is driven. That is, the speaker drive signal y ₁ ~y ₄ is D / A converted by the D / A converter 17a to 17d, an analog switch 28a~28
d, and output to the loudspeakers 7a to 7d via the amplifiers 18a to 18d, whereby the loudspeakers 7a to 7d reduce noise transmitted from the front wheels 2a, 2b and the rear wheels 2c, 2d into the vehicle interior 6. The secondary sound of the opposite phase is output to reduce the noise in the passenger compartment 6.

Next, in FIG. 6, first, in step _S61 , a reference signal is detected. That is, the first digital filter 12 inputs the reference signal x, and
A reference signal r _lm (see equations (4) and (5)) filtered in accordance with the number of combinations of transfer functions between 8h and the speakers 7a to 7d is generated and output to the microprocessor 16. In stiff S ₆₂ simultaneously, the detection of interior noise e is performed. That is, when the secondary sound is output by the loudspeakers 7a to 7d as described above, the noise in the vehicle interior 6 is canceled out, and the residual noise is detected by the microphones 8a to 8h as a residual signal. Then, a noise signal e ₁ which is an output signal of the microphones 8a to 8h.
To e ₈ is amplified by the amplifier 14a-14h, A /
A / D conversion is performed by the D converters 15a to 15h, and input to the microprocessor 16.

Next, in step _S63 , the square of the sound pressure e ²
(See equation (2)).

Next, in step _S64 , the filter coefficient is updated. That is, the microprocessor 16 calculates the above equation (5) based on the summation of the reference signal r _lm and the sound pressure e ² so as to minimize the sum of the squares of the sound pressure. The filter coefficient W is updated sequentially. Therefore, the reference signal x is filtered by the adaptively updated filter coefficient W,
The loudspeakers 7a to 7d can be driven, whereby the noise in the passenger compartment 6 can be reduced.

In such control, the transfer function G changes as described above, for example, when there is sudden braking, sudden start, or the like. Therefore, the change amount and the change speed of the transfer function G exceed the threshold value and suddenly change. Predicted by changes in vehicle acceleration,
The adaptive operation by the microprocessor 16 is stopped.

The relationship between the change in the vehicle body acceleration and the change in the transfer function will now be described.

FIG. 7 shows an experimental result of the relationship between the transfer function and the frequency and time. The transfer function is a transfer function G between the suspension which is the noise source and the microphones 8a to 8h which are the evaluation points, the frequency is the frequency of the signal relating to the noise generation state of the noise source, and the time represents the time during traveling. ing. During traveling, when the vehicle body changed posture due to braking, a change in the transfer function G was observed as indicated by an arrow B. Looking at this change in G at a specific frequency f, a phase change ΔΦ and a gain change ΔG as shown in FIG.
Therefore, by knowing the change state of the acceleration and deceleration of the vehicle body, it is possible to predict the posture change of the vehicle body, and it is possible to predict the phase change ΔΦ and the gain change ΔG due to the change of the transfer function G. Therefore, if the vehicle acceleration rapidly changes in a short time, the phase change and the gain change occur rapidly in a short time. In such a case, the adaptive operation of the microprocessor 16 and the generation of the control sound will be stopped. It is assumed that.

FIG. 9 is a flowchart for stopping the adaptive operation and the control sound generation, and will be described below with reference to this flowchart.

The flowchart of FIG. 9 is executed by a fixed time interruption process with respect to the flowchart of the speaker drive signal output of FIG. However, the flowchart of FIG. 5 may be adapted to stop the adaptive operation only when the change state of the vehicle body acceleration exceeds a predetermined state.

First, in step S ₉₁ , the determination circuit 23 reads a change in vehicle acceleration detected by the vehicle acceleration sensor 21. Step S vehicle acceleration change amount in ₉₂ is determined whether above a predetermined threshold, the process returns to step S ₉₁ if exceeded, step S ₉₃ if Uwamaware
Then, it is determined whether or not the change speed of the vehicle body acceleration exceeds a predetermined threshold. If the change speed does not exceed the predetermined threshold value, the process returns to step _S91 . If the change speed exceeds the predetermined threshold value, the vehicle body acceleration rapidly changes in a short time. For example, it can be predicted that the vehicle body posture changes greatly due to sudden braking or sudden start, _Move to step _S94 . In step _S94 , a signal is sent from the determination circuit 23 to the stop switch 25, the stop switch 25 is turned off, and the adaptive operation of the microprocessor 16 is stopped. At the same time the filter coefficients W ₀ of the adaptive digital filter 13 at this time the microprocessor 16
In reading rare, W ₀ is stored in step S _95. Then, control goes to a step _S160 . Step S ₁₆₀
Then, a signal is sent from the determination circuit 23 to the stop switch 26, the stop switch 26 is turned off, and the operation of generating the control sound is stopped.

As described above, when the change state of the vehicle body acceleration exceeds the predetermined state and there is a large change in the posture of the vehicle body,
The adaptive operation of the microprocessor 16 is stopped, and no control is performed during that time. Therefore, in road noise control with a large amount of calculation, it is possible to avoid a state in which the adaptive operation of the microprocessor 16 cannot follow even if the transfer function G changes abruptly. can do.

Then, steps _S96 and _S97 are executed to determine whether or not the vehicle body attitude has returned to the original state. In step _S96 , the change in the vehicle body acceleration is read again, and in step _S97 , it is determined whether the amount of change exceeds a predetermined threshold. Variation is step S ₉₆ is repeated since the continuing sudden braking or sudden acceleration state once exceeds the threshold value, adaptive operation remains stopped. If the amount of change is below a threshold end rapid acceleration or sudden braking state, W ₀ which is stored the operation proceeds to Step S ₉₈ for vehicle body posture change is eliminated based on this is called, adaptive operation in step S _99, and step becomes the control sound generating operation in S ₁₅₉ is started. Thus, the adaptive operation start is performed with respect to the filter coefficients W ₀ which stores in step S _95, though whether to perform an adaptive operation as there is no sudden acceleration or sudden braking or the like, to maintain the follow-up of the control Can be.

Second Embodiment FIG. 10 is a block diagram according to a second embodiment, which corresponds to FIG. 3 of the first embodiment.

In the second embodiment, the drive signals to the loudspeakers 7a to 7d, which are the control wave sources, are corrected according to the change state of the transfer function G. Therefore, in this embodiment, the changeover switch 33 and the storage correction circuit 35 are added.

The storage correction circuit 35 constitutes means for storing in advance a plurality of correction values according to the change state of the transfer function G. The judgment circuit 23, the changeover switch 33, and the storage correction circuit 35 Means is provided for selecting a correction value according to the change state of the function and correcting the drive signal to the control wave source.

The storage correction circuit 35 stores a correction value obtained as follows. That is, as shown in FIGS. 7 and 8, phase changes and gain changes due to sudden acceleration and sudden braking can be obtained in advance by experiments, and these are shown for all frequencies in FIGS. 11 (a) and 11 (b). It is.

Then, an inverse Fourier transform is performed based on the phase change (a) and the gain change (b) to obtain FIG.
As shown in (c), an impulse response function under a certain condition can be obtained. Then, a plurality of such impulse response functions are obtained in accordance with a change in the transfer function G due to sudden acceleration or sudden braking, and these are stored in the storage correction circuit 35 as a map.

Accordingly, in this embodiment, when a change occurs in the transfer function G, an impulse response function as a correction value is selected according to the change, and an appropriate loudspeaker drive signal is obtained by convolving the impulse response function with the filter coefficient of the adaptive digital filter 13. What you can get.

That is, when the reference signal x is filtered by the filter coefficient W _mi of the adaptive digital filter 13, the speaker drive signal is

(Equation 6) However, the speaker drive signal when the gain change is further convolved is

(Equation 7) Thus, an appropriate speaker drive signal according to the change of the transfer function can be obtained.

Hereinafter, description will be made with reference to the flowchart of FIG.

[0083] The difference from the flowchart of the flowchart in FIG. 9, and it was added call to the filter coefficients in step S _116, switching of the changeover switch 33 in step S _117, the convolution of ΔG in step S _118, S ₁₅₉ , _{S160 The} control sound generation stop and start steps are eliminated.

[0084] First, in step S ₁₁₁ to read the vehicle acceleration change performed, step S _112, step S ₁₁₃
Changing state by comparing the threshold value is determined whether took place rapidly increases, adaptive operation stops in step S ₁₁₄ if exceeding the threshold, read the filter coefficients W ₀ is performed in. Adaptive operation stop performed by the stop switch 25 by a signal from the decision circuit 23 is OFF, read the filter coefficients W ₀ is performed by the microprocessor 16.

[0085] filter coefficients W ₀ was read as described above in step S ₁₁₅ is stored.

In step _S116 , a filter coefficient corresponding to the vehicle body acceleration change amount is called from the memory. That is, the change state of the vehicle body acceleration determined by the determination circuit 23, that is, the change state of the transfer function G is input to the storage correction circuit 35, and any one of the impulse stored as shown in FIG. The response function is called.

In step _S117 , the changeover switch 33 is switched to the ΔG side, that is, the memory correction circuit 35 side, by the signal from the judgment circuit 23.

[0088] convolute impulse response functions called as above in step S ₁₁₈ to the output of the adaptive digital filter 13 as described above (7), correcting the drive signal of the loudspeaker 7a to 7d.

[0089] Step S ₁₁₉ to step S ₉₆ in FIG. 9,
Step S ₁₂₀ is the same step S _97, step S ₁₂₁ in the step S _98, the description will step S ₁₂₂ corresponds respectively to the step S ₉₉ is omitted.

Accordingly, even when the vehicle body attitude greatly changes due to sudden acceleration, sudden braking, etc., and the transfer function G changes, the drive signals of the loudspeakers 7a to 7d can be corrected in accordance therewith, and control deterioration is suppressed. In addition, appropriate silencing control can be performed. In addition, since the adaptive operation of the microprocessor 16 is not affected by the change of the transfer function G, the controllability can be maintained.

The table of the plurality of correction values according to the change state of the transfer function G, in other words, the table of the gain change ΔG is not only the table at the time of braking and rapid acceleration as described above, but also the road surface condition, right turn, It can also be set in relation to a left turn or the like. This is shown below together with the table for braking and rapid acceleration.

[0092]

[Table 1] Accordingly, appropriate control can be performed irrespective of the change of the transfer function G in the same manner as described above even when the road surface condition changes, right turn, left turn, and the like, and the control followability is not impaired. it can.

In the first and second embodiments, the vehicle body posture change state detecting means is replaced with the vehicle body acceleration sensor 21.
3 and FIG. 10, the throttle opening sensor 27 for detecting the throttle opening of the engine, the brake sensor 29 for detecting the amount of depression of the brake, or the steering angle and angular velocity sensor 3 for steering.
1 or any of the active suspension control signals (not shown) or a combination thereof. That is, the throttle opening sensor 2
7, the posture change due to sudden acceleration can be known, and the posture change due to sudden braking can be known by detecting the amount of brake depression by the brake sensor 29. Further, the steering angle By detecting the steering angle and the angular velocity of the steering with the angular velocity sensor 31, it is possible to know the attitude change due to rolling of the vehicle body 1, and further, it is possible to know the attitude change due to sudden braking, rolling, etc., by the control signal of the active suspension. Because you can.

Third Embodiment FIG. 13 shows a block diagram according to a third embodiment in a state similar to FIG. In this embodiment, the vehicle body posture change state detecting means is constituted by a road surface sensor 37. The road surface sensor 37 is constituted by, for example, a transmitting / receiving device of an ultrasonic wave, and a detection signal of a road surface condition is determined by the determination circuit 23
The drive signals to the loudspeakers 7a to 7d are corrected according to the change of the transfer function G by determining whether the front wheel 2a, 2b and the rear wheel 2c, 2b have a convex input or a concave input. Is what you do.

Next, a further description will be given with reference to the flowchart of FIG.

This flowchart is also processed by a fixed time interruption or the like, similarly to the flowcharts shown in FIGS. First, in step _S141 , a road surface change is read by the determination circuit 23 from the output signal of the road surface sensor 37.

In step _S142 , the judgment circuit 23
In, whether a change of the road surface change exceeds a predetermined threshold value is determined, if exceed returns to step S _141, the process proceeds to step S ₁₄₃ if Uwamaware.

In step _S143 , the input wheel is determined. The process proceeds to step S ₁₄₄ when the road surface changes an input from the left and right wheels over right and left wheels, and m = 1and 2, provided on the control by input from the right and left wheels. If it is determined that the wheel is the right wheel, the process proceeds to step _S145 and m = 1.
And prepare for control by input to the right wheel. When the input is made to the left wheel, the process _proceeds to step _S146 , where m = 2, to prepare for control by input to the left wheel.

In step _S147 , the stop switch 25 is turned off by the output from the judgment circuit 23, and the filter coefficient W of the adaptive digital filter 13 at that time is changed.
_{m (0)} is read in, W _{m (0)} is stored in step S _148. The storage of the filter coefficient Wm ₍₀₎ is intended to cause the adaptive operation to be performed from the filter coefficient immediately before the stop of the adaptive operation when the adaptive operation is restarted after the road surface change disappears as described above.

In step _S149 , the storage correction circuit 35 changes the transfer function G based on the output from the decision circuit 23,
In other words, the gain change ΔG corresponding to the amount of change in the road surface change is called. This call is made in steps S ₁₄₄ and S
_145, called according to the setting of S _146. Step S
_{At 150} , the changeover switch 33 is switched to the ΔG side, and the adaptive operation is stopped. Adaptive operation stop of the step S _0.99 front wheels 2a detection by the road surface sensor 37, the time delay until the irregularities input to 2b takes place. Step S
_{At 151} , the gain change ΔG is convoluted with the output of the adaptive digital filter 13 as in the equation (7).

In step _S152 , it is determined whether or not control for the rear wheels has been completed. If not, in step _S153 , the front and rear wheels 2a, 2b, 2c, 2 are determined.
Based on the wheel base and the vehicle speed during the period d, the time from when the front wheel has the irregularity input to when the rear wheel has the irregularity input is delayed. Similarly, steps _S149 , _S150 , and _S151 are executed, and the roadway from the road surface is executed. The speaker drive signal is corrected in accordance with the change of the transfer function due to the unevenness input. Therefore, the transfer characteristic between the vibration measurement point and the microphones 8a to 8h when the suspension receives the unevenness input from the road surface becomes equal to the characteristic obtained by combining the filter coefficient W and the impulse response function of the gain change ΔG. Even if a large input is input to the wheel, the silencing volume can be controlled without deteriorating.

At step _S154 , a change in the road surface is read again. At step _S155 , it is determined whether or not the amount of change exceeds a threshold value, and it is determined whether or not the suspension is in the original state. If the suspension is not in the original state, the process _proceeds to step _S149 , and the above control is repeated again. If the suspension is in the original state, the process proceeds to step _S156 . Step _S156
Then, the filter coefficient Wm ₍₀₎ at the time of stopping the adaptive operation stored in step _S148 is called, and the adaptive operation is started from the filter coefficient Wm ₍₀₎ in step _S157 .

Therefore, the adaptive operation of the microprocessor 16 is not affected by the change of the transfer function G, and the control followability can be maintained.

The present invention is not limited to the above embodiment.

For example, even if the evaluation point for noise reduction is spatially separated from the microphone, the control can be performed by estimating the residual noise at the evaluation point based on a predetermined value.

The algorithm for updating the filter coefficients of the adaptive digital filter is not limited to the LMS algorithm in the time domain, and other algorithms such as the LMS algorithm in the frequency domain can be applied.

Further, the present invention can be applied to the control of unpleasant wave of vibration.

[0108]

As is apparent from the above description, according to the first aspect of the present invention, when the change state of the transfer function from the source of the unpleasant wave to the evaluation point according to the running state of the vehicle exceeds a predetermined threshold value , the adaptive controller Since the adaptive operation is stopped, the adaptive operation of the adaptive controller is not affected by the change of the transfer function, and it is possible to suppress the deterioration of the control .
The size of the apparatus can be reduced without impairing the controllability .

According to the second aspect of the present invention, it is possible to respond to the running state of the vehicle.
Since the drive signal to the control wave source can be corrected according to the changed state of the transfer function, appropriate control can be performed regardless of the change of the transfer function. Moreover, since a plurality of correction values corresponding to the change state of the transfer function are stored in advance and the correction is performed using the stored correction value, the adaptive operation of the adaptive controller is not affected by the change of the transfer function and the road noise is not affected. etc., vehicle running at most the number of filter coefficients to be updated in the noise control or the like based on random signal
High-speed processing can be performed with a small device without compromising the controllability of the middle control .

According to the third aspect of the present invention, the change state of the transfer function can be detected based on the posture change state of the vehicle body.

According to the fourth aspect of the present invention, a change in the posture of the vehicle body can be detected by the vehicle body acceleration sensor.

According to the fifth aspect of the present invention, the change in the attitude of the vehicle body can be detected by the throttle opening amount of the engine detected by the throttle opening sensor.

According to the sixth aspect of the present invention, the posture change state of the vehicle body can be detected by the brake depression amount detected by the brake sensor.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a state in which an active unpleasant wave control device according to a first embodiment is applied to a vehicle.

FIG. 2 is a control block diagram according to the first embodiment.

FIG. 3 is a control block diagram of a main part according to the first embodiment.

FIG. 4 is a control block diagram of a main part according to the first embodiment.

FIG. 5 is a flowchart of speaker driving.

FIG. 6 is a flowchart of updating a filter coefficient.

FIG. 7 is a three-dimensional graph showing a change in a transfer function.

FIG. 8 is a graph showing a phase change and a gain change at a specific frequency.

FIG. 9 is a flowchart of stopping an adaptive operation.

FIG. 10 is a block diagram according to a second embodiment.

FIG. 11 is a graph of a phase change, a gain change, and an impulse response function.

FIG. 12 is a flowchart according to a second embodiment.

FIG. 13 is a block diagram according to a third embodiment.

FIG. 14 is a flowchart according to a third embodiment.

FIG. 15 is a block diagram according to a conventional example.

FIG. 16 is a control block diagram when applied to an automobile.

FIG. 17 is a graph showing a change in a transfer function.

[Explanation of symbols]

7a Loudspeaker (control wave source) 7b Loudspeaker (control wave source) 7c Loudspeaker (control wave source) 7d Loudspeaker (control wave source) 8a Microphone (residual unpleasant wave detecting means) 8b Microphone (residual unpleasant wave detecting means) 8c Microphone (residual) Unpleasant wave detection means) 8d microphone (residual unpleasant wave detection means) 8e microphone (residual unpleasant wave detection means) 8f microphone (residual unpleasant wave detection means) 8g microphone (residual unpleasant wave detection means) 8h microphone (residual unpleasant wave detection means) 13 Adaptive Digital Filter 16 Microprocessor (Adaptive Controller) 21 Vehicle Acceleration Sensor (Vehicle Body Posture Change State Detecting Means) 23 Judgment Circuit (Determining Means, Transfer Function Change State Predicting Means) 25 Stop Switch (Stop Means) 27 Throttle Sensor (Body Posture changing state detecting means) 29 brake sensor (vehicle body posture changing state detecting means) 31 steering angle and the acceleration sensor (vehicle body posture change state detection means)

────────────────────────────────────────────────── ─── Continued on the front page Examiner Masahiro Ishihara (56) References JP-A-4-11292 (JP, A) JP-A-5-61486 (JP, A) JP-A-4-234098 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) B60R 11/02 B64C 1/40 F01N 1/06 G10K 11/178

Claims (7)

(57) [Claims] 1. A control wave source for generating a control wave that interferes with a noise or vibration unpleasant wave to reduce an unpleasant wave at an evaluation point, means for detecting a residual wave at a predetermined position after the interference, and Means for detecting a signal relating to an unpleasant wave occurrence state, an adaptive digital filter for filtering the detection signal for the unpleasant wave occurrence state with a predetermined filter coefficient and outputting a signal for driving the control wave source, and the residual unpleasant wave detection means Adaptive control for sequentially updating the filter coefficient of the adaptive digital filter so as to reduce the output signal of the residual unpleasant wave detection means using a predetermined control algorithm based on the output signal of the adaptive digital filter and the output signal of the unpleasant wave generation state detection means Based on a detection signal of a means for detecting a running state of the vehicle.
Means and the predicted change in state of a predetermined threshold to predict the change in state of a transfer function of a rating point from the discomfort wave source Zui
Means for judging whether or not the value exceeds a predetermined value;
Wherein at least one of means for stopping the adaptive operation of the adaptive controller or a means for stopping the control wave upon receiving a signal output from the determination means when it is determined that the threshold value is exceeded is provided. Type uncomfortable wave control device. 2. A control wave source for generating a control wave for interfering with a noise or vibration unpleasant wave to reduce an unpleasant wave at an evaluation point, a unit for detecting a residual unpleasant wave at a predetermined position after the interference, and an unpleasant wave source Means for detecting a signal relating to an unpleasant wave occurrence state, an adaptive digital filter for filtering the detection signal of the unpleasant wave occurrence state by a predetermined filter coefficient and outputting a signal for driving the control wave source, and the residual unpleasant wave detection Adaptively updating filter coefficients of the adaptive digital filter so as to reduce the output signal of the residual unpleasant wave detection means using a predetermined control algorithm based on the output signal of the means and the output signal of the unpleasant wave generation state detection means And a detection signal of means for detecting a running state of the vehicle.
Means and, a plurality of pre-stored unit a correction value corresponding to the change state of the transfer function, the predicted change in state predetermined for predicting the changing state of the transfer function to the evaluation point from the discomfort wave source based on No. A means for selecting the correction value when it is determined that the threshold value exceeds the threshold value and correcting the drive signal to the control wave source. 3. The active-type unpleasant wave control device according to claim 1, wherein the prediction by the transfer function change state predicting means is based on a detection signal of a means for detecting a posture change state of the vehicle body. Active unpleasant wave control device. 4. The active-type unpleasant wave control device according to claim 3, wherein the posture change state detecting means of the vehicle body is a vehicle body acceleration sensor provided at a predetermined position of the vehicle body and detecting an acceleration of the vehicle body. Active unpleasant wave control device. 5. The active-type unpleasant wave control device according to claim 3, wherein the attitude change state detecting means of the vehicle body is a throttle opening sensor for detecting a throttle opening of an engine. Type uncomfortable wave control device. 6. The active unpleasant wave control device according to claim 3, wherein said vehicle body posture change state detecting means is a brake sensor for detecting a brake depression amount. Control device. 7. The active-type unpleasant wave control device according to claim 3, wherein the attitude change state detecting means of the vehicle body is a steering angle and angular velocity sensor for detecting a steering angle and an angular velocity of a steering. Active unpleasant wave control device.