JP3535533B2 - Active vibration noise 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 vibration noise control device, and more particularly to active vibration noise control for actively controlling vibration noise generated in a vehicle interior due to traveling of a vehicle and reducing the vibration noise. Regarding the device.

[0002]

2. Description of the Related Art In recent years, vehicle interior vibration noise (for example,
In order to reduce road noise), an active vibration noise control device has been developed which reduces vibration noise by generating vibration noise having a phase opposite to that of the vibration noise by, for example, a speaker and interfering with each other.

Conventionally, as an active vibration control device of this type, as shown in FIG. 5, a noise sensor 21 for detecting noise from a noise source (vibration source) and a noise detected by the noise sensor 21 are referred to. An adaptive control circuit 22 that is input as a signal and that generates a canceling signal that has a transfer characteristic that has a phase opposite to the transfer characteristic of the noise, and a speaker 2 that emits a canceling sound based on the canceling signal that is generated by the adaptive control circuit 22.
3 and a microphone 24 for detecting an error between the canceling sound generated by the speaker 23 and the noise are known as main parts (for example, Table 1-5).
No. 01344).

In the above conventional active vibration control device,
The noise (primary noise) detected by the noise sensor 21 is A
The signal is sampled by the / D converter 25 and input to the adaptive control circuit 22 as a standard signal (reference signal) x (n) of digital data. The cancellation signal generated as described above is output from the adaptive control circuit 22, converted into an analog signal by the D / A converter 26, amplified by the amplifier 27, and canceling sound (secondary noise) is emitted from the speaker 23. .

On the other hand, the microphone 24 receives the synthesized sound of the canceling sound and the noise from the speaker 23, and outputs the synthesized sound ε.
Is amplified by an amplifier 28, sampled by an A / D converter 29, and an error signal e of digital data is output.
It is taken out as (n) and fed back to the adaptive control circuit 22. That is, the error signal indicates a cancellation error between the primary noise and the secondary noise, and in the active vibration control device, the noise of the noise is changed by changing the characteristic of the cancellation signal so that the error signal becomes the minimum value. It is being reduced.

The adaptive control circuit 22 includes an FIR type adaptive digital filter (hereinafter referred to as “ADF”) 22 ₁ and an FIR filter 22 ₂ for compensating the delay characteristic from the speaker 23 to the microphone 24 peculiar to this control system. The filter coefficient is C (∧)), and the FIR filter 22 ₂
Based on the reference signal r (n) and the error signal e (n) filtered by
S: Least Mean Square) and the LMS processing unit 22 ₃ for updating the filter coefficient of the ADF 22 _{1 so} that the error signal e (n) becomes the minimum value.

ADF 22 ₃ and FIR filter 22
₂ is actually a general-purpose DSP (Digital Signal Processo)
It can be realized by r).

[0008]

However, in the above-described conventional active vibration control device, the vibration noise control is performed even when the vehicle is running at a low speed and the vehicle interior noise due to road noise is not felt. Done. Also,
As shown in FIG. 6, when the vehicle is running at low speed, the engine speed is low and the amount of power generated by the generator is low, so the amount of electric power charged in the battery is low. Since the cancellation signal output from the speaker has a large amount of low frequency components, the active vibration control device consumes a large amount of power and the battery load increases, as shown in FIG. 7.

Therefore, if the active noise control is continued during low-speed traveling, the power consumption is larger than the power generated by the generator, and the stored power in the battery is consumed, so that the battery may run out. Also, when the vehicle speed falls below the predetermined speed, the amount of noise of road noise itself decreases and the charge and discharge balance of the battery is maintained, but since noise sensors are generally installed on the suspension of the vehicle body, vibration noise other than road noise is referred to. By being input as a signal to the noise sensor, a canceling sound unrelated to the road noise is generated from the speaker. For example, when the vehicle stops, the suspension moves due to passengers getting on and off, and when this noise is picked up by the noise sensor, a canceling sound unrelated to the road noise is generated.

The present invention has been made in view of the above problems, and it is possible to reduce the burden on the battery when the vehicle is traveling at a low speed, and to suppress the generation of unnecessary canceling noise unrelated to road noise. An object is to provide an active vibration control device.

[0011]

In order to achieve the above object, the present invention provides a canceling sound for generating a canceling sound having a phase opposite to that of the vibrating noise generated in the vehicle interior due to traveling of the vehicle. In an active vibration noise control device having a generating means, a vehicle speed sensor for detecting the speed of a vehicle, and when the vehicle speed detected by the vehicle speed sensor is below a predetermined speed, the canceling sound generating means is controlled to generate a canceling sound. And a control means for stopping.

Preferably, the canceling sound generating means is
A noise detector that detects vibration noise and outputs it as a reference signal.
And a canceling sound that generates a canceling sound having a phase opposite to that of the vibration noise.
The noise that is not removed by the generation means and the cancellation noise
Error signal detecting means for detecting and outputting as an error signal,
The reference signal and the error signal are input, and the error signal is
Outputs a canceling signal that becomes small to the canceling sound generating means.
The adaptive control means,
Adjust the amplitude of the signal or at least one of the cancellation signals
By controlling the amplitude adjusting means to
By setting the amplitude of at least one of the cancellation signals to 0
It is characterized by stopping the generation of the canceling sound. Further, a noise detecting unit that detects vibration noise and outputs it as a reference signal, a canceling sound generating unit that generates a canceling sound having a phase opposite to that of the vibration noise, and a noise that is not removed by the canceling sound are detected, and an error signal Vibration noise control having an error signal detecting means for outputting as a noise and an adaptive control means for inputting the reference signal and the error signal and outputting a canceling signal for minimizing the error signal to the canceling sound generating means. In the device, comparing means for comparing the reference signal with a predetermined value, amplitude adjusting means for adjusting the amplitude of at least one of the reference signal or the cancellation signal, and when the reference signal is larger than the predetermined value, the amplitude By controlling the adjustment means,
And a control means for stopping the generation of the canceling sound by setting the amplitude of at least one of the reference signal and the canceling signal to 0.

[0013]

[0014]

With the above construction, the invention according to claim 1 stops the generation of the canceling noise by the control means when the traveling speed of the vehicle becomes a predetermined speed or less.

[0015]

According to the third aspect of the invention, when the total power consumption of the various electric load devices exceeds the power generation amount, the control means stops the generation of the canceling noise.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of an active vibration control device according to the present invention.

In the figure, reference numeral 1 is a noise sensor for detecting road noise of a vehicle, and an output side of the noise sensor 1 is connected to an input side of an A / D converter 2 for converting an analog output of the noise sensor 1 into a digital signal. The output side of the A / D converter 2 is connected to the input side of the amplitude adjusting circuit 3 that controls the amplitude of the digital output of the A / D converter 2.
The control output of the ANC control control circuit 4 for controlling the control amount of active vibration control (hereinafter referred to as "ANC") is input to the amplitude adjustment circuit 3, and the input signal of the amplitude adjustment circuit 3 is input according to this control output. The amplitude of is adjusted. The ANC control control circuit 4 includes a vehicle speed sensor 5
Is connected, and the ANC control control circuit 4 sends an output according to the vehicle speed detected by the vehicle speed sensor 5 to the amplitude adjusting circuit 3 as a control output. Further, the output side of the amplitude adjusting circuit 3 is connected to the input side of the adaptive control circuit 6.

The adaptive control circuit 6 is constituted by the ADF 6 ₁ and the FIR filter 6 ₂ and LMS processor 6 _3, the output of the amplitude adjustment circuit 3 is branched into two, one is connected to the input side of the ADF 6 ₁ , The other is connected to the input side of the FIR filter 6 ₂ . The output side of the FIR filter 6 ₂ is LM
It is connected to the input side of the S processing unit 6 _{3 and} the output side of the LMS processing unit 6 ₃ is connected to the input end for updating the filter coefficient of the ADF 6 ₁ . The output side of the ADF 6 ₁ is connected to the input side of the D / A converter 7 which converts its digital output into an analog signal, and the output side of the D / A converter 7 is connected to the input side of the speaker 9 via the amplifier 8. There is.

Further, a microphone 10 for picking up vibration noise that is not removed by the canceling sound output from the speaker 9 is provided, the output side of which is connected to the A / D converter 12 via the amplifier 11, and the output side thereof is the above-mentioned. It is connected to the input side of the LMS processing unit 6 ₃ .

As described above, the amplitude adjusting circuit 3 is the ANC.
The amplitude of the input signal (which is the reference signal x (n) in this embodiment) is adjusted according to the control output of the control control circuit 4, but in this embodiment, when the vehicle speed sensor 5 falls below a predetermined speed, ANC control is performed. The control circuit 4 outputs a control signal for setting the amplitude of the input signal to 0. With this configuration, when the vehicle speed falls below a predetermined speed, the reference signal has more vibration components other than the road noise than the vibration components of the road noise that is the control target to be reduced, and vibrations other than the control target The vibration is input as a reference signal and L
This is because the input of the reference signal is stopped before the filter coefficient of the ADF 6 ₁ is changed by the MS processing unit 6 ₃ .

The operation of the active vibration control device configured as described above will be described.

The vibration noise detected by the noise sensor 1 is converted into a digital reference signal x by the A / D converter 2.
It is input to the amplitude adjusting circuit 3 as (n). Reference signal x
The amplitude of (n) is adjusted according to the control output of the amplitude adjusting circuit 3, and is output to the ADF 6 ₁ and the FIR filter 6 ₂ . That is, as described above, the amplitude of the reference signal x (n) is set to 0 when the vehicle speed detected by the vehicle speed sensor 5 becomes equal to or lower than a predetermined speed, while the reference signal x (n) exceeds the predetermined speed. x (n) is output as it is.

The reference signal x '(n) whose amplitude has been adjusted in this way is subjected to delay compensation according to the transmission delay characteristic from the speaker 9 to the microphone 10 by the FIR filter 6 _{2 and} is then LMS as a signal r (n). It is output to the processing unit 6 _3. The LMS processor 6 _3, ADF 6 ₁ of the filter coefficient by LMS algorithm based on the delay compensation signal r (n) and will be described later error signal e (n) is calculated updated. Amplitude adjusted reference signal x '
(N) is filtered by the ADF 6 ₁ based on its filter coefficient and output as a cancellation signal y (n), converted into an analog signal by the D / A converter 7, amplified by the amplifier 8, and canceled by the speaker 9. Will be output.

The canceling sound output from the speaker 9 interferes with the vehicle interior noise, and the vehicle interior noise that is not removed even by the canceling sound is detected as an error signal ε by the microphone 10, is amplified by the amplifier 11, and is A / D converter. 12 becomes a digital error signal e (n) and LMS
It is input to the processing unit 6 _3.

As described above, according to this embodiment,
By stopping the input of the reference signal when the speed of the vehicle becomes lower than the predetermined speed, it is possible to suppress the cancellation noise with many low frequency components from being generated from the speaker and prevent the battery from being overloaded. be able to.

FIG. 2 is a block diagram showing the schematic construction of the second embodiment of the active vibration control system according to the present invention. In the figure, elements corresponding to those in the block diagram of FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The active vibration control system of this embodiment is different from the first embodiment in that the amplitude control circuits 3 ₂ and 3 ₃ and various electric loads such as defrosters, headlights, wipers, air conditioner fans and electromagnetic clutches are used. A total power meter 13 that measures the total amount of power consumed by the device, a power generator 14 that detects the amount of power generated by the generator (power generation amount), an air conditioner air volume detection device 15 that detects the air volume of the air conditioner, An audio output detecting device 16 for detecting an audio output and a window position detecting device 17 for detecting an open / closed state of a window glass are added. That is, in this embodiment, when the load on the battery is constantly monitored and the battery is overloaded, other factors than the influence of the canceling sound on the road noise, for example, window glass as shown in FIG. The active vibration control is configured to be stopped when the influence of wind entrainment when the is open is greater.

The amplitude adjusting circuit 3 ₁ is arranged between the A / D converter 2 and the adaptive control circuit 6, and the amplitude adjusting circuit 3 ₂ is arranged in the ADF 6 ₁
And the D / A converter 7 between the amplitude adjusting circuit 3 _{3 and} A
It is connected between the / D converter 12 and the LMS processing unit 6 ₃ . The output side of the ANC control control circuit 4 ₁ is connected to the control input sides of the amplitude adjusting circuits 3 ₁ , 3 ₂ and 3 ₃ , and the vehicle speed sensor 5 is connected to the input side of the circuit 4 ₁ via the bus line 18. Total power meter 13, power meter 1
4, an air conditioner air volume detection device 15, an audio output detection device 16 and a window position detection device 17 are connected.

The operation of the active vibration control device configured as described above will be described.

The operation of this active vibration control apparatus is mainly different from that of the active vibration control apparatus of the first embodiment only in the control operation of the ANC control control circuit 4 _1.
The control operation of the C control control circuit 4 ₁ will be described.

The ANC control control circuit 4 ₁ receives the detection values of various detection devices from the bus line 18, compares these detection values, and determines the control output to the amplitude adjusting circuits 3 ₁ , 3 ₂ , 3 ₃ . . That is, the total power consumption of various electric load devices detected by the total power meter 13 and the power generator 14
When the total power consumption exceeds the amount of power generation and the battery is overloaded, the speed of the vehicle detected by the vehicle speed sensor 5 is determined by comparing the amount of power generated by the generator detected by When the influence of road noise becomes negligible below the speed, when the fan motor of the air conditioner rotates faster due to the detection value of the air conditioner air volume detection device 15 and the noise does not show the effect of ANC, the audio output detection device When the audio output is large due to the detection value of 16 and the effect of ANC does not appear, and when the effect of ANC does not appear due to the wind noise coming in from the window by opening the window glass at high speed running, ANC The control control circuit 4 ₁ sends a control output for setting the amplitude of the input signal to 0 to the amplitude adjusting circuits 3 ₁ , 3 ₂ , 3 ₃ .

Further, when the speaker for audio is also used as the speaker for generating the canceling sound, the output by the audio and the output of the canceling sound may be superposed and the speaker may be damaged. Therefore, when the audio output is large, the ANC is changed. Stopping makes it possible to protect the speaker.

When the vibration sensor is attached to the suspension to control the road noise, when there is an excessive input to the vibration sensor, for example, when a bump is overridden, for example, as shown in FIG. Reference signal x
By comparing (n) with a predetermined upper limit value by the comparator 20, this excessive input is detected and the amplitudes of the input signals of the amplitude adjusting circuits 3 _{1 to} 3 ₃ are set to 0 by the ANC control control circuit 4 ₁ . With this configuration, since the filter coefficient of the ADF 6 ₁ is not updated by a temporary excessive input, it is possible to suppress the divergence of ANC that may occur after passing the excessive input.

[0036]

As described above, according to the first aspect of the invention, with respect to the vibration noise generated in the vehicle interior due to the traveling of the vehicle, a canceling noise having a phase opposite to the vibration noise is generated. In the active vibration noise control device having the canceling sound generating means, the vehicle speed sensor for detecting the speed of the vehicle, and when the vehicle speed detected by the vehicle speed sensor is equal to or lower than a predetermined speed, the canceling sound generating means is controlled to cancel. Since it has a control means for stopping the generation of the sound, it prevents the charge / discharge balance of the battery from being broken when the vehicle is running at a low speed and an excessive load is applied to the battery, and suppresses the generation of an unnecessary canceling sound unrelated to the road noise. The effect that becomes possible is produced.

[0037]

Further, according to the invention of claim 3 , noise detecting means for detecting the vibration noise and outputting it as a reference signal, and canceling sound generating means for generating a canceling sound having a phase opposite to that of the vibration noise, Error signal detecting means for detecting noise that is not removed even by the canceling sound and outputting it as an error signal, and inputting the reference signal and the error signal, generating a canceling signal for canceling the canceling signal that minimizes the error signal. In an active vibration noise control device having an adaptive control means for outputting to a means, a power consumption measuring means for measuring the total power consumption of various electric load devices mounted on a vehicle, and a power generation by a generator mounted on the vehicle. Power generation amount measuring means for measuring the amount, amplitude adjusting means for adjusting the amplitude of at least one of the reference signal or the cancellation signal, and the measured total power consumption is the measured power generation amount. Control means for controlling the amplitude adjusting means to set the amplitude of at least one of the reference signal and the canceling signal to 0, thereby stopping the generation of the canceling sound. Prevents the balance from being overloaded and overwhelming the battery.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of an active vibration control device according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a second embodiment of the active vibration control device according to the present invention.

FIG. 3 is a diagram showing the relationship between the vehicle speed of a vehicle and the volume of vehicle interior noise due to various noise sources.

FIG. 4 is a block diagram showing a schematic configuration of another embodiment of the active vibration control device according to the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a conventional active vibration control device.

FIG. 6 is a diagram showing a relationship between an engine speed and electric power generated by a generator.

FIG. 7 is a diagram showing the relationship between the output frequency of the active vibration control device and its used current.

[Explanation of symbols]

3,3 _1, 3 _2, 3 ₃ amplitude adjustment circuit (control means, the amplitude adjustment
Adjusting means ) 4,4 ₁ ANC control control circuit (controlling means) 5 Vehicle speed sensor 13 Total power meter (power consumption measuring means) 14 Electricity meter (power generation measuring means) 15 Air conditioner air volume detection device 16 Audio output detection device 17 Window Position Detection Device 20 Comparator (Comparison Means)

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-11772 (JP, A) JP-A-6-222782 (JP, A) JP-A-60-190123 (JP, A) JP-A-62-1 88638 (JP, A) JP 5-216484 (JP, A) JP 4-34598 (JP, A) JP 4-34599 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G10K 11/178 F01N 1/00 H04B 1/16

Claims (3)

(57) [Claims] 1. An active vibration noise control device having a canceling noise generating means for generating a canceling noise having a phase opposite to that of the vibration noise generated in the vehicle interior due to traveling of the vehicle. And a control means for controlling the canceling sound generation means to stop the generation of the canceling sound when the vehicle speed detected by the vehicle speed sensor is equal to or lower than a predetermined speed. Vibration noise control device. 2. The canceling sound generating means, A noise detector that detects the vibration noise and outputs it as a reference signal.
Means of delivery A canceling sound generator that generates a canceling sound having a phase opposite to that of the vibration noise.
Dan, Detects noise that is not removed by the cancellation noise and
Error signal detecting means for outputting as a signal, The reference signal and the error signal are input, and the error signal is
Outputs a canceling signal that becomes small to the canceling sound generating means.
Adaptive control means The control means is Vibration of at least one of the reference signal and the cancellation signal
By controlling the amplitude adjusting means for adjusting the width, the reference signal or
Or the amplitude of at least one of the cancellation signals can be set to zero.
It is characterized by stopping the generation of cancellation sound by
The active vibration noise control device according to claim 1. 3. A noise detecting means for detecting vibration noise and outputting it as a reference signal, a canceling sound generating means for generating canceling sound having a phase opposite to that of the vibration noise, and noise not removed even by the canceling sound. Error signal detecting means for outputting as an error signal, and inputting the reference signal and the error signal,
In an active vibration noise control device having an adaptive control means for outputting a cancellation signal that minimizes the error signal to the cancellation sound generation means, the total power consumption of various electric load devices mounted on the vehicle is measured. Power consumption measuring means, power generation amount measuring means for measuring the power generation amount of a generator mounted on the vehicle, amplitude adjusting means for adjusting the amplitude of at least one of the reference signal and the cancellation signal, and the measured When the total power consumption exceeds the measured power generation amount, the amplitude adjusting means is controlled to set the amplitude of at least one of the reference signal and the cancellation signal to 0.
And a control means for stopping the generation of the canceling sound.