JP3281122B2 - Vehicle vibration reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration reducing device for a vehicle in which vibration, that is, noise of the vehicle is reduced by an interference effect using vibration for reduction.

[0002]

2. Description of the Related Art In a vehicle, in particular, an automobile or the like in which noise caused by an engine, that is, first vibration is a problem, a reducing vibration, that is, second vibration is generated from a speaker or the like, and the first vibration and second vibration are generated. It has been proposed to reduce the first vibration by interference with the first vibration.

[0003] In this type of vibration reduction apparatus, as shown in Japanese Patent Application Publication No. 1-501344, a reference signal generator for extracting a signal from a vibration source, that is, a signal corresponding to the first vibration, as a reference signal. A microphone for picking up vibration in a predetermined space where noise caused by the first vibration is a problem, a speaker for generating a second vibration toward the predetermined space, and a second vibration for outputting from the speaker. And an algorithm operation device for sequentially optimizing the filter coefficients of the filter. That is, the adaptive digital filter adjusts the gain, phase, and the like of the reference signal according to the reference signal to generate the second vibration, while reducing the filter coefficient of the adaptive digital filter so that the vibration detected by the microphone is reduced. Are sequentially optimized by the algorithm operation device. In general, a least-squares method is used as an algorithm for optimization.

The above-described vibration reducing device has the advantage that vibration can be reduced widely in response to various vibrations, but the amount of calculation is extremely large. , A high-end arithmetic unit is required. In particular, as the number of speakers and microphones increases, the amount of calculation increases in series.

In view of the above, the applicant of the present invention has considered that in a vehicle, the first vibration to be canceled is generally periodic, such as engine vibration, and the vibration for reduction is generated. The amount of calculation for
In addition, we have developed a vibration reduction device for vehicles that does not require a high-end arithmetic unit.

[0006] That is, due to the rotation of the engine, the first
A period detecting means for detecting a period of the first vibration generated by the vibration source; and a second vibration source (reducing vibration generating source) for outputting a second vibration for reducing the vibration energy of the first vibration, for example, a speaker. A vibration detecting means for detecting vibration of a place such as a vehicle room to reduce vibration, for example, a microphone, and a vibration energy of a second vibration outputted from a second vibration source is set for each cycle detected by the cycle detecting means. The apparatus includes a setting unit, and a correction unit that corrects an output of the setting unit based on the vibration detection unit and a transfer characteristic between the vibration detection unit and the second vibration source.

With this configuration, although it is not possible to cope with sporadic or sudden vibrations, the second vibration, that is, the waveform generation processing for the reduction vibration, and the microphone are performed based on the cycle detected by the cycle detecting means. The vibration process to be picked up in one cycle can be performed collectively,
Calculation for optimizing the vibration waveform of the second vibration becomes extremely simple, and as a result, the periodic vibration can be sufficiently reduced without using a sophisticated arithmetic unit.

[0008]

However, in the above-described apparatus for reducing periodic vibration, when the period of the first vibration is short, the time until the vibration converges so that the vibration can be sufficiently reduced is obtained. Although the period is short, if the period of the first vibration is long, the number of data for one period of the vibration for reduction increases, that is, the amount of data to be calculated increases, and it takes a considerable time for the vibration to converge. Will be done. That is, the data value for determining the vibration waveform of the vibration for reduction is set for each predetermined sampling period. However, when the engine is running at a low speed, one cycle of the vibration for reduction is long, so the waveform of the vibration for reduction is determined. Therefore, the number of data values to be processed also increases, which requires a long time for vibration convergence.

The present invention has been made in view of the above circumstances. In the present invention, in which the reduction vibration is corrected, that is, optimized for each period of the periodic vibration to be reduced, the time until the vibration converges is reduced. It is an object of the present invention to provide a vehicle vibration reduction device that can be made as short as possible.

[0010]

To achieve the above object, the present invention has the following configuration as a first configuration. That is, according to a first aspect of the present invention, there is provided a vehicle vibration control device for reducing periodic vibration generated due to rotation of an engine in a predetermined space of the vehicle, wherein the rotation of the engine is controlled. Cycle detection means for detecting a cycle, a reduction vibration source for outputting reduction vibration for reducing periodic vibration generated from the engine, vibration detection means for detecting vibration in the predetermined space, For information corresponding to the waveform signal for one cycle of the second vibration, that is, for output data that is an n-dimensional vector having n waveform amplitude values as constituent elements, n is a sampling cycle for time series conversion described later. Setting means for setting the multiplication value of the first vibration to be the same as the cycle of the first vibration detected by the cycle detecting means, and setting by the setting means in the previous control cycle. Correction means for correcting the output data based on the output of the vibration detection means and the transfer characteristics between the vibration detection means and the second vibration source, for each cycle; and By arranging the components of the output data for each sampling period, the second
Output means for performing time-series conversion to a vibration waveform signal and outputting a waveform signal obtained by the conversion from the second vibration source; and sampling when the engine rotation speed is high when the engine rotation speed is low. Sampling period changing means for changing the sampling period so as to be larger than the period.

In order to achieve the above object, the present invention has the following configuration as a second configuration. That is, according to a second aspect of the present invention, there is provided a vehicle vibration control device for reducing periodic vibration generated due to rotation of an engine in a predetermined space of the vehicle, wherein the rotation of the engine is controlled. Cycle detection means for detecting a cycle, a reduction vibration source for outputting reduction vibration for reducing periodic vibration generated from the engine, vibration detection means for detecting vibration in the predetermined space, For information corresponding to the waveform signal for one cycle of the second vibration, that is, for output data that is an n-dimensional vector having n waveform amplitude values as constituent elements, n is a sampling cycle for time series conversion described later. Setting means for setting the multiplication value of the first vibration to be the same as the cycle of the first vibration detected by the cycle detecting means, and setting by the setting means in the previous control cycle. Correction means for correcting the output data based on the output of the vibration detection means and the transfer characteristics between the vibration detection means and the second vibration source, for each cycle; and An output unit for arranging the constituent elements of the output data for each sampling period to perform time-series conversion to a waveform signal of a second vibration, and outputting a waveform signal obtained by the conversion from the second vibration source; Data number changing means for changing the data number n so that the data number n does not exceed a certain value even when the number is small.

[0012] On the premise of the first configuration, the transfer characteristic is formed by an interpolation method based on a predetermined reference sampling period so that the transfer characteristic corresponds to the sampling period changed by the sampling frequency changing means. The apparatus may further include a characteristic correcting unit.

On the premise of the first configuration, there is provided an input low-pass filter through which a signal from the vibration detecting means passes, and an output low-pass filter through which a signal to the reduction vibration generating source passes. The cutoff frequency of each low-pass filter can be set to be changed according to the sampling cycle changed by the sampling cycle changing means. On the premise of the first configuration, the data of the transfer characteristics can be set in advance for each sampling cycle.

[0014]

According to the first aspect of the present invention, when the engine speed is reduced and one cycle of the vibration for reduction becomes longer, the data of the vibration for reduction is increased by increasing the sampling cycle. The value does not increase excessively, and the speed up to the optimization of the vibration for reduction can be increased by that much, and the time until the convergence of the vibration can be shortened.

According to the second aspect of the invention, when the number of revolutions of the engine decreases and one cycle of the oscillation for reduction becomes longer, the data value of the oscillation for reduction is limited so as not to exceed a predetermined value. Accordingly, the data value of the vibration for reduction does not extremely increase, and the speed up to the optimization of the vibration for reduction can be increased by that much, and the time until the convergence of the vibration can be shortened.

According to the third aspect of the present invention, the load on the memory can be reduced as compared with the case where transfer characteristic data, that is, impulse response data is stored for each sampling cycle. According to the fourth aspect of the present invention, unnecessary frequency components can be reliably cut, and a sufficient vibration reduction effect can be obtained. According to the fifth aspect of the present invention, the data of the transfer characteristic, that is, the impulse response data is made extremely appropriate, and the effect of reducing the vibration can be sufficiently obtained.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, an automobile 1 is a four-seater passenger car having a driver's seat 3, a passenger seat 4, and left and right rear seats 5 and 6 in a cabin 2. An in-line four-cylinder gasoline engine 8 is mounted on an engine room 7 formed at the front of the vehicle body, and its ignition coil is indicated by reference numeral 9.

The engine 8 is a noise source that generates a periodic vibration according to the engine speed, that is, a first vibration source. The cabin 2 is a predetermined space in which vibration of the engine 8 should be reduced. For this purpose, five speakers 11 and eight microphones 12 are installed in the cabin 2 as a predetermined space. The speaker 11 is a second vibration source that generates a second vibration for reducing engine noise in the vehicle compartment. Then, the microphone 12 is used as vibration detecting means for detecting actual vibration of the vehicle interior. In the embodiment, the speaker 11 is also used for audio sources such as a cassette deck and a tuner, but may be provided exclusively for reducing vibration.

The automobile 1 has a control unit U mounted thereon using a microcomputer. The input / output relationship for the control unit U is shown in FIG.
The control unit U has a control unit 20 including a CPU. The control unit 20 receives a signal from the primary coil of the ignition coil 9, that is, an ignition pulse signal corresponding to the engine speed via a waveform shaping circuit 21 and a cycle calculation circuit 22, and receives a signal from each microphone 12. , An amplifier 23, a low-pass filter 24, and an A / D converter 25. The output signal from the control unit 20 is D
The signal is output to the speaker 11 via the / A converter 26, the low-pass filter 27, and the amplifier 28.

The control unit 20 optimizes the second vibration (reducing vibration) to be output from the speaker 11 so that the vibration detected by the microphone 12 is reduced. Hereinafter, the control unit 20
Will be described. First, a description will be given of the generation of the basic second vibration, that is, the generation of the second vibration on the assumption that the period obtained according to the IG pulse is constant.

Generation of Second Vibration (Basic) FIG. 3 is a block diagram showing the control unit 20.
For simplicity of description, the case where one speaker 11 and one microphone 12 are used is shown.

The control unit 20 adjusts the cycle of the vector y of the speaker input signal y to be output to the speaker 11 based on the result input from the cycle measuring circuit 22 (step 1,
The following step is abbreviated as S), and a built-in processor converts the matrix h of the impulse response h which is the transfer characteristic between the microphone 12 and the speaker 2 into a time series h (S).
2).

Next, the control unit 20 is a processor that sequentially optimizes the vector y based on the time series h of the impulse response h and the microphone output signal e input from the microphone 12 (S
3) After that, the vector y is converted into a time series y to be a speaker input signal y (S4) and output to the speaker 11.

The speaker 11 receives the input signal y
Is reproduced as anti-noise Z. On the other hand, the microphone 12
The noise d and the anti-noise Z cancel each other out, and the noise whose vibration energy is reduced is detected, and the result is output as a digital microphone output signal e to a processor built in the control unit 20. Hereinafter, the processor again executes the above step 3
And step 4 are repeated to obtain the speaker input signal y
Are sequentially optimized, and the vector y of the speaker input signal y is set so that the value of the microphone output signal e finally becomes zero.

Next, the calculation of the algorithm of the above steps performed by the control unit 20 will be described below.

First, the sampling period of the microphone output signal e of the microphone 12 by the control unit 20 is set to Δt. Assuming that the impulse response h, which is the transfer characteristic between the microphone 12 and the speaker 11, converges to 0 within a finite time J △ t, and the value of the impulse response h after the elapse of j △ t after the impulse input is given Let h _j be the noise d, which is the first vibration generated from the engine 8, the anti-noise Z, which is the second vibration generated from the speaker 11 when the speaker input signal y is given, and the noise d at that time. The relationship between the k-th sample value e (k) of the microphone output signal e at time k can be expressed by the following equation (1).

E (k) = d (k) + Z (k) = d (k) + matrix h ^T · matrix y (k) (1) where matrix h = [h ₀ h ₁ h ₂ ... H _J-1 ] ^T matrix y (k) = [y (k) y (k-1) y (k-2).
(K-J + 1)] ^T d (k): component of noise d included in e (k) Z (k): component of anti-noise Z included in e (k) y (k) : K-th sample value of speaker input signal y Therefore, Z (k) in equation (1) is represented by the following equation (2).

[0028]

(Equation 1)

Since the noise d is a periodic noise having a certain period N △ t, the anti-noise Z for reducing the vibration energy of the noise d, the speaker input signal y, and the same period as the noise d It must be a periodic oscillation and a periodic signal with N △ t.

Therefore, the following equation (3) holds for the speaker input signal y. y (k) = y (K-qN) = y (k) y (k-1) = y (k-qN-1) = y (k + N-1) y (k-2) = y (k -qN-2) = y (k + N-2) (3) ... y (k-N + 1) = y (k- (q + 1) N + 1) = y (k + 1) where q = 0, 1, 2,... Therefore, equation (1) is expressed as follows: e (k) = d (k) + vector h ^T · time series y (k ) (4) where y (k) = [y (K) y (K + N-1) y (K + N-2)
・ ・ Y (K + 1)] ^T

[0031]

(Equation 2)

Here, Q is the minimum value of the integer q satisfying J ≦ (q + 1) N.

Next, the K + i-th sample value e of the microphone output signal e at the time k + i after the time i has further elapsed from the time k.
(K + i) (where i = 1, 2,...) Is given by the following equation (5)
Can be represented by

E (k + i) = d (k + i) + vector h T · time series y (k + i) = d (k + i) + time series h (i) T · time series y (k ) ..... (5) where the time series y (k + i) = [ y (k + i) 'y (k + i' -1) y (k + N-1) y (k + N -2) ············ y (k + i ' +1)] T time series h (i) = [bar h i ' bar h i + 1 ' ···· bar h
N + 1 bar -h 0 Ba -h 1 · · · · bar -h i '-1] T Note that, i' is an integer remainder of the division of the i in N.

By the way, in the equation (5), k merely represents an arbitrary initial point of the microphone input signal e. Therefore, when k = 0 and i is replaced with k again, the following equation (6) is obtained.

E (k) = d (k) + time series h (k) ^T · time series y (0) = d (k) + time series h (k) ^T · vector y where vector y = [y (0) y (N-1) y (N-2)... Y (1)] ^T = [y ₀ y _N-1 y _N-2 ... Y ₁ ] ^T where the next evaluation Introduce a function. F = E [e (k) ² ] = E [d (k) + time series h (k) ^T · vector y] = E [d (k) ² ] +2 vectors y ^T · E [d (k) · when the series h (k)] + vector y ^T · E [time series h (k) · time series h (k) ^T] vector y ······ (7) However, E [] is the expected value (E is an expected operator). From equation (7), the vector y of this evaluation function
Is given by the following equation (8). ∂F / ∂ vector y = 2E [d (k) · time series h (k)] + 2E [time series h (k) · time series h (k) ^T ] vector y = 2E [time series h (k) { d (k) + time series h (k) ^T vector y｝] = 2E [time series h (k) · e (k)] (8) where E [time series h (k) If the time series h (k) · e (K) is used as the instantaneous estimated value of [e (K)], the speed having the period N △ t (ie, the number of elements N) that gives the minimum value of F is obtained. The value of the vector y, which is the output signal vector, can be optimized by repeatedly calculating the following recurrence formula (9) based on the steepest descent method.

Vector y (K + 1) = Vector y (k) −μ · e (k) · Time Series h (k) (9) where μ / 2 is a convergence coefficient.

The recurrence formula (9) obtained in this manner corrects the setting of the vibration energy of the anti-noise for reducing the vibration energy of the noise by the processor as the data processing device built in the control unit 20. In this case, it is replaced with a simpler algorithm as shown below.

First, a pair of the speaker 11 and the microphone 1
When 2 is used, recurrence equation (9) is replaced by the following equation (10). y _{(k−j + QN)} ^′ (k + 1) = y _{(k−j + QN)} ^′ · (k) −μ · e (k) · h _j (10) At this time, the processor In k, for example, the following four operation procedures are performed.

Operation 1: The speaker input signal y _k ^′ (k) is output to the speaker 11. Operation 2: A microphone output signal e (K) is input from the microphone 12. Operation 3: Engine 22 input from cycle measurement circuit 22
The integer value closest to a value obtained by multiplying the rotation cycle of Ord / Δt or 1 / (Ord · Δt) is set to N. Operation 4: The recurrence formula (10) is calculated for j = 0, 1, 2,..., J-1. Here, k ′ and (k−j + QN) ′ are respectively k (k−
j + QN) is an integer remainder when N is divided by N, and Ord is an arbitrary constant for setting the lowest order of the noise to be reduced with respect to the engine speed.

Next, when a plurality of speakers 11... And microphones 12 are used, for example, based on the steepest descent method,

[0042]

(Equation 3)

As an instantaneous estimated value of

[0044]

(Equation 4)

Using, the evaluation function

[0046]

(Equation 5)

The optimum value of the vector y ₁ , which is the first speaker output signal vector for minimizing the following equation, is represented by the following recurrence equation (11).
Is calculated by iterative calculation.

[0048]

(Equation 6)

[0049] However, y _lk ^': first spin at time k - Ka input signal e _m: m-th microphone output signal h _LMJ: first spin - force between-the m microphone impulse response j △ t time after Value L: Number of speakers M: Number of microphones J: Integer value indicating that the impulse response between all the speakers and microphones converges to 0 within a finite time Δt Also, the vector _yl = [y _{l 0 yl N-1 yl N-2} ... y
_{l 1} ] ^T time series h _lm (k) = [bar h _{lm k '} bar h _{lm k' + 1} ...
Bar h _{lm N + 1} Bar h _{lm 0} Bar h _{lm 1} ... Bar h _lm
k'-1] ^T In addition, bus _{-h lm 0 = h lm 0 +} h lm N + ···· h lm QN server _{-h lm 1 = h lm 1 +} h lm N + 1 + ··· h lm QN + ₁ ... ... ... ... server _{-h lm j-QN-1 =} h lm j-QN-1 + h lm j- (Q-1) N-1 + ··· + h _{lm j-1} bar h _{lm j-QN} = h _{lm j-QN} + h _{lm j- (Q-1) N} + ・ ・ ・ +0 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Bar _{lmN -1} = _{hlmN -1} + _{hlm2N -1} +... +0 l = 1, 2,..., Lm = 1, 2,. Formula (9) is replaced by the following formula (12).

[0050]

(Equation 7)

At this time, the processor performs, for example, the following four operation procedures at time k.

Operation 11: speaker input signal y _1k ^′ (k),
^{_{y 2k '(k), ····}} , y lk' (k) , respectively first spin - force, the second spin - outputs to mosquitoes - mosquitoes, ..., a L spin. Operation 12: microphone output signals e ₁ (k), e ₂ (k),..., E _M (k)
Are input from the first microphone, the second microphone,..., The Mth microphone, respectively. Operation 13: the engine 2 input from the cycle measurement circuit 22
An integer value closest to a value obtained by multiplying the rotation cycle of 2 by Ord / △ t or 1 / (Ord △ Δt) is defined as N. Operation 14: 1 = 1, 2,... L and j = 0,
The recurrence formula (12) is calculated for 1, 2,..., J-1. Also, the plurality of speakers 11 ... and the microphones 12 ...
・ ・ When using

[0053]

(Equation 8)

As the instantaneous estimated value of α, time series h _1k ^′ (k)
・ Using e _k ^' (k), the evaluation function is calculated based on the steepest descent method.

[0055]

(Equation 9)

The optimum value of the vector y ₁ , which is the first speaker output signal vector for minimizing the following equation, is expressed by the following recurrence equation (13).
Is calculated by iterative calculation. Vector y ₁ (k + ₁₎ = vector _{y 1 (k) -μ · α} · time series ^{_{h 1k "(k) · e}} k" (k) ···· (13) However, k "is, the k M Is a value obtained by adding 1 to the integer remainder obtained by dividing by 1. The recurrence formula (13) can be calculated in a shorter time than the recurrence formula (11).

Therefore, the recurrence equation (9) is replaced by the following equation (14). _{y 1 (k-J + QN} ) '(k + 1) = y 1 (K-j + QN)' (k) -μ · α · e k (k) · h 1k "j ····· ( 14) At this time, the processor performs, for example, the following four operation procedures at the time.

Operation 21: speaker input signal y _1k ^′ (k), y
_2k ^′ (k),..., Y _Lk ^′ (k)
, The second speaker,...,..., The L-th speaker. Operation 22: The microphone output signal e _k ^" (k) is input from the k-th microphone. Operation 23: the engine 2 input from the cycle measurement circuit 22
An integer value closest to a value obtained by multiplying the rotation cycle of 2 by Ord / Δt or 1 / (Ord · Δt) is defined as N. Operation 24: 1 = 1, 2,..., L and j = 0,
The recurrence formula (14) is calculated for 1, 2,..., J-1. Therefore, the operation of the above algorithm is the recurrence formula (9),
(11) and (13) or the recurrence formulas (10), (12) and (14), which are simplified versions of these recurrence formulas, need only be iteratively calculated, so that the calculation time for speaker input control is reduced. It is possible to do.

[0059]Control of sampling cycle change (Figs. 4 to
7) FIG. 4 shows the sampling cycle (sampling frequency).
The control part for changing according to an engine rotation speed is shown.
In FIG. 4, the sampling clock generator 29
The control contents are shown in a flowchart of FIG. First,
In Q (step-the same applies hereinafter) 1 in FIG.
The engine speed R is the cycle (engine speed) measurement circuit 2
2 is input. Thereafter, in Q2, shown here
According to the equation, according to the engine speed R (rpm)
The current sampling frequency F (Hz) is calculated. This
In the formula, R_O Is the reference engine speed, F₀ Is the reference engine
The sampling frequency and int at the
Means that the result should be a rounded integer. This
Then, in Q3, the sampling cycle calculated in Q2
The wave number F is controlled by the control unit (A
NC control unit) 20 and a control for selecting impulse response data.
It is output to the control unit 41.

As shown in FIG. 5, the control section 41 stores a plurality of impulse response data, selects impulse response data corresponding to the sampling frequency F received from the sampling clock generator 29, and The selected impulse response data is output to the ANC controller 20 (see the flowchart of FIG. 7).

Here, the low-pass filter 2 shown in FIG.
The cutoff frequencies of 4, 27 are changed so that they are always 1/3 to 1/4 of the sampling frequency changed as described above, and unnecessary frequency components are reliably removed.

[0062]Interpolation of impulse response data (Fig. 8, Fig.
9) Stores impulse response data for each sampling frequency
Doing so increases the load on the memory. For this reason,
Based on the quasi-impulse response data, by interpolation,
The sampling frequency, that is, the engine speed
Preferably, the pulse response data is obtained by calculation. Figure
8 is an impulse response data (data) shown as old data.
New impulse by primary interpolation based on
FIG. 4 shows a method for determining response data (15 data items).
It is shown schematically. That is, the new data after interpolation is the same
Within the response duration T, the waveform based on the old data
The old data is generally extended or contracted so that the force is maintained.
Lengthened.

Since the primary interpolation method itself is well known, its schematic meaning is shown in FIG. This figure 9
, The data value at the phase k is h (k) and the phase k + 1
Assuming that the data value at (h) is h (k + 1), this data value h
Consider an imaginary line X connecting (k) and h (k + 1). In the new data, the primary interpolation value at the phase α1 is β1 on the virtual line X, and the primary interpolation value at the phase α2 is β2 on the virtual line X. The reliability of the new data after interpolation is 1
Although the secondary interpolation is sufficiently secured, it is also possible to perform the secondary interpolation or the tertiary interpolation.

Another example of interpolation of impulse response data (FIG.
10 to FIG. 13) In the interpolation shown in FIG. 8, since the interpolation is performed for all the values, the calculation amount of the interpolation increases. For this reason,
Interpolation can be performed only for the difference in the number of data. That is, when the number of data increases,
It is sufficient to insert data into the old data by an increasing number at equal intervals, and to interpolate the data value at the insertion position with the old data values before and after that. When the number of data decreases, the data value is deleted from the old data at equal intervals by the reduced number,
The data value of the new data at the position to be deleted may be interpolated between the data value at the deleted position and the data value at the position next to the deleted position.

FIG. 10 is a flowchart for determining whether to insert or delete data, where n ₀ is the old data.
De of data - data the number, n ₁ is the new de - other de - which is another number. Of course, F is the sampling frequency and T is the response duration. Since the meaning of FIG. 10 is clear, Q2
4. Except for Q25, further description is omitted.

FIG. 11 shows the details of the data insertion process in Q24 of FIG. In FIG. 11, Q
Reference numeral 33 denotes a process for determining the insertion position. The formula is set so that the insertion data is dispersed in the old data at equal intervals according to the number of the insertion data.

The processing from Q33 to Q37 is the determination of the data insertion position, and the insertion position is determined from the end of the data position. If the determination in Q37 is NO, the data insertion position does not come. In this case, the old data
The data value of the data is set as it is as the data value of the new data. The time when the determination in Q37 is YES is the time when the data is to be inserted. In this case, the old data values before and after the insertion position are determined by the processing in Q39 or Q40. Is used to determine the data value at the insertion position. Note that Q3
8. The processing of Q40 means interpolation between the last data value of the old data and the first data value (the next data value adjacent to the last data value). Is the first data value).

The processing of Q41 to Q42 is for performing the next data insertion after one data insertion is completed, and when the judgment of Q42 is YES, all the data are processed. This means that data insertion is completed.

FIG. 12 shows the details of the data deletion process in Q27 of FIG. In the control contents shown in FIG. 12, Q53 is a process for determining a deletion position, and is a formula for dispersing the deletion positions at equal intervals in the old data according to the number of data deletions. It is set. Also,
The process of Q54 is a temporary storage process for using the data value at the position to be deleted for subsequent interpolation. Until the determination of Q58 becomes NO, it means that the data has not yet arrived at the deletion position counted from the last one, and the data value not at this deletion position is used as it is as the data value of the new data. .

The time point of YES in the judgment of Q58 is the time when the data reaches the deletion position. At this time, according to the equation shown in Q59, the data value of the new data at the deletion position becomes 1 Interpolated next. Q60 and Q61 are processing for repeatedly performing the setting and interpolation of the next deletion position.
When the determination in step 1 is YES, all the processes to be deleted are completed.

FIG. 13 shows the sampling frequency for calculation used in the calculation.
FIG. 3 schematically shows an example of a case where the ratio is changed at a predetermined ratio according to the engine speed. That is, although the physical sampling frequency is not different from that of the above-described embodiment, for example, data processing for optimizing the vibration for reduction is performed only once in four sampling timings. By thinning out sampling, an effect similar to that of actually changing the sampling frequency is obtained. In FIG. 13, when the engine is running at a high speed, a normal operation is performed in accordance with the basic sampling frequency described above, and when the engine is running at a medium speed, thinned sampling is performed so as to have a ratio of 1/2 of the basic sampling frequency (two sampling timings). (Execution of vibration reduction optimization at one time), thinning sampling at 1/4 of the basic sampling frequency at low engine speed (only once every four sampling timings) Calculation for vibration optimization). As a result, the reduction length, that is, the data length (the number of data) of the output waveform from the ANC control unit 20 is set to a value within a small range of a predetermined upper limit value, and the calculation speed for optimization is sufficiently increased. be able to.

FIG. 14 and FIG. 15 show details of control contents by thinning sampling. First, in FIG. 14, it is determined whether the current engine speed R is larger than twice the predetermined reference engine speed Rb (Q72) or smaller than half (Q76). Then, based on the result of this determination, the sampling frequency F at the time of the reference engine speed Rb is doubled (Q
73) or 1/2 times (Q77), and the reference engine speed Rb is updated in Q74 or Q78. Thereafter, in Q75, Q7
The sampling frequency is changed to 3 or the sampling frequency set in Q77. Of course, the ANC control unit 20 executes the calculation of the vibration for reduction at the changed sampling frequency, whereby the waveform data of the vibration for reduction is substantially shortened. Incidentally, when thinning is not performed, the data length of the output waveform becomes significantly longer as the engine speed decreases, as shown by the dashed line in FIG.

FIG. 15 shows the modification of the impulse response data according to the sampling frequency changed in FIG.
In FIG. 15, F ₀ is an initial (maximum) sampling frequency corresponding to the upper limit of FIG. 13, and based on the sampling frequency corresponding to the upper limit,
Impulse response data corresponding to other engine speeds (but only in the same sampling ratio range) is corrected. That is, as a percentage reduction of the sampling ratio r shown in Q82 in Fig. 15, the impulse response data of at F ₀ - the data de - from data number of a predetermined number de - Remove number data (the deletion position The data value is set to 0).

The number of impulse response data at the time of F ₀ is “a number obtained by subtracting 1 from 2 N” (N is an integer), and the processing of Q84 to Q88 is performed by the new impulse response data. de of data - data value, the impulse response data of when the F ₀ -
This is a process of directly replacing data values (setting of positions and data values). The processing in Q90 to Q91 is processing for setting the data value at the position to be deleted to 0, and the processing in Q89 is for confirming whether or not all the processing has been completed.

Although the embodiments have been described above, the source of vibration for reduction is not limited to the speaker, but may be a variable displacement type actuator interposed between the engine and the vehicle body.

[Brief description of the drawings]

FIG. 1 is a top view of a vehicle to which the present invention is applied.

FIG. 2 is an overall control system diagram for generating a vibration for reduction.

FIG. 3 is a block diagram showing a configuration of a portion for optimizing the vibration for reduction in FIG. 2;

FIG. 4 is a diagram showing a control system for changing a sampling frequency.

FIG. 5 is a diagram showing a state in which impulse response data is stored according to a sampling frequency.

FIG. 6 is a flowchart for changing a sampling frequency according to the engine speed.

FIG. 7 is a flowchart for selecting impulse response data according to a sampling frequency.

FIG. 8 is a diagram schematically showing a case where impulse response data is obtained by overall interpolation.

FIG. 9 is a view for explaining the meaning of primary interpolation.

FIG. 10 is a flowchart for determining whether or not to perform interpolation;
G.

FIG. 11 is a flowchart for obtaining impulse response data by partial insertion and interpolation.

FIG. 12 is a flowchart for obtaining impulse response data by partial deletion and interpolation.

FIG. 13 is a diagram schematically illustrating thinning sampling.

FIG. 14 is a flowchart for determining a sampling frequency for calculation to be a sampling sampling.

FIG. 15 is a flowchart showing correction of impulse response data according to thinning sampling.

[Explanation of symbols]

1: automobile 2: cabin 8: engine (vibration source) 11: speaker (vibration generation source for reduction) 12: microphone (vibration detection means) 20: vibration generation circuit for reduction 24: input-side low-pass filter 27 : Output low-pass filter 41: Control unit (selection of impulse response data according to sampling vehicle)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-274184 (JP, A) JP-A-6-282284 (JP, A) JP-A-6-337683 (JP, A) JP-A-6-337683 266376 (JP, A) JP-A-4-352197 (JP, A) JP-A-4-109124 (JP, A) JP-A-4-347559 (JP, A) JP-A-5-39710 (JP, A) JP-A-5-80777 (JP, A) JP-A-4-203406 (JP, A) JP-A-4-287733 (JP, A) JP-A-1-191198 (JP, A) JP-A-1-257798 (JP, A) JP-T4-505221 (JP, A) JP-T 5-503622 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G10K 11/178 B60K 11 / 02 F16F 15/02 G10K 11/16 F01N 1/00 F01N 1/06

Claims (5)

(57) [Claims] 1. A vehicle vibration control device for reducing a periodic vibration generated due to rotation of an engine in a predetermined space of the vehicle, comprising: a period detecting means for detecting a rotation period of the engine; A reducing vibration source for outputting a reducing vibration for reducing the generated periodic vibration; a vibration detecting means for detecting the vibration in the predetermined space; and a waveform signal corresponding to one cycle of the second vibration. Information,
That is, an n-dimensional matrix having n waveform amplitude values as constituent elements
For output data that is a
Multiplied by the sampling period during time series conversion
The same as the period of the first vibration detected by the period detecting means
A setting unit configured to set as the set by the setting means in the previous control cycle
Correcting means for correcting output data for each cycle based on an output of the vibration detecting means and a transfer characteristic between the vibration detecting means and the second vibration source; and the output corrected by the correcting means. Required data structure
By arranging the elements at every sampling cycle, the second vibration
Time-series converted to a waveform signal of
Output means for outputting a waveform signal from the second vibration source, and the sampling period when the engine speed is low is
And a sampling cycle changing means for changing the sampling cycle so as to be longer than the sampling cycle when the engine rotation speed is high . 2. A vibration control device for a vehicle for reducing a periodic vibration generated due to rotation of an engine in a predetermined space of the vehicle, comprising: a period detecting means for detecting a rotation period of the engine; A reducing vibration source for outputting a reducing vibration for reducing the generated periodic vibration; a vibration detecting means for detecting the vibration in the predetermined space; and a waveform signal corresponding to one cycle of the second vibration. Information,
That is, an n-dimensional matrix having n waveform amplitude values as constituent elements
For output data that is a
Multiplied by the sampling period during time series conversion
The same as the period of the first vibration detected by the period detecting means
A setting unit configured to set as the set by the setting means in the previous control cycle
Correcting means for correcting output data for each cycle based on an output of the vibration detecting means and a transfer characteristic between the vibration detecting means and the second vibration source; and the output corrected by the correcting means. Required data structure
By arranging the elements at every sampling cycle, the second vibration
Time-series converted to a waveform signal of
An output means for outputting a waveform signal from the second vibration source , wherein the data number n is constant even when the engine speed is low.
Data number change to change the data number n so as not to exceed
Means for reducing the vibration of the vehicle. 3. The sampling frequency changing means according to claim 1, wherein said transfer characteristic is determined by said sampling frequency changing means.
Will correspond to the changed sampling period.
As described above, the interpolation method based on the predetermined reference sampling period
A vibration control device for a vehicle , further comprising a transfer characteristic correcting unit to be formed . 4. An input side roper according to claim 1, wherein a signal from said vibration detecting means is passed.
Signal to the filter and the vibration source for reduction.
And a low-pass filter on the output side,
The cutoff frequency of the pass filter is
According to the sampling period changed by the period changing means
A vibration control device for a vehicle, characterized in that the vibration control device is changed by a change . 5. The method according to claim 1, wherein the data of the transfer characteristic is set in advance for each sampling cycle.
A vibration control device for a vehicle .