JP2000172281A - In-compartment sound controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a in-compartment sound controller capable of easily installing an in-compartment noise reducing device and forming a pleasant space by generating a comfortable engine sound in accordance with the taste of a crew and sounds synchronized with the engine sound. SOLUTION: An Ig pulse signal is inputted to a generation-sound original signal generating part 5, in which a generation-sound original signal is generated based on the Ig signal to be inputted to a generation-sound signal synthesizing part 6, in which the generation-sound original signal is synthesized as a generation-sound signal to be outputted to a spealer 4 via a D/A converter, a filter circuit and an amplifier circuit and then a generation signal is reproduced to be generated in the speaker. When the crew makes the generation sound a different sound, the sound characteristic selecting part 3 of the switch panel part of an audio device and an air conditioner or the like in a compartment is operated and necessary signals are inputted to a sound characteristic setting part 7, in which the setting of respective characteristics is performed so that the generation-sound original signal generating part 5 and the generation- sound signal synthesizing part 6 become the characteristic which is selected by the crew with the sound characteristic selecting part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle interior sound control device for controlling vehicle interior sound, particularly a vehicle interior sound generated mainly by an engine, so as to make the vehicle interior a comfortable sound field for occupants.

[0002]

2. Description of the Related Art Conventionally, in order to realize a comfortable cabin space for occupants, it has been practiced to reduce the cabin noise, and recently, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-178845. , LMS (Least Mean Squ
are) algorithm or MEFX-LMS (Mul
A vehicle interior noise reduction device using a tiple error filtered X-LMS (algorithm) algorithm has been proposed, and some of the devices have begun to be put into practical use.

[0003] In such a vehicle interior noise reduction apparatus utilizing the LMS algorithm, a signal having a high correlation with the engine vibration is used as a noise vibration source signal (primary source) to mitigate the vehicle interior noise generated mainly by engine vibration. , And cancels the noise from the primary source using an adaptive filter, and generates the noise from the speaker. Then, the noise reduction state at the listening point is detected as an error signal by the microphone, and the filter coefficient of the adaptive filter is updated by the LMS algorithm from the error signal and the primary source to optimize the noise reduction at the listening point. ing.

For this reason, in a vehicle interior noise reduction device using the above LMS algorithm, a DSP (Digit
al Signal Processor).

[0005]

By the way, the interior space that is comfortable for the occupant is not only reduced by reducing the noise in the interior of the vehicle as described above, but also by generating a sound that is comfortable for the occupant. It is feasible. In particular,
Apart from music and the like reproduced by the audio device, some engine sounds give a passenger a comfortable feeling. However, since the engine sound is determined by the vehicle, it has been difficult to effectively use the engine sound as a comfortable sound in the vehicle interior.

Further, if such a comfortable sound generating device is provided in conjunction with the above-mentioned vehicle interior noise reducing device, the occupant can selectively use the device according to the situation at that time, and can enjoy a more comfortable drive. .

The present invention has been made in view of the above circumstances, and a vehicle interior noise reduction device is easily provided, and a comfortable engine sound according to a passenger's preference and a sound synchronized with the engine sound can be generated. It is an object of the present invention to provide a vehicle interior sound control device capable of forming a vehicle interior space that is comfortable for an occupant.

[0008]

According to a first aspect of the present invention, there is provided a vehicle interior sound control apparatus for detecting an engine rotation signal and generating an original signal of the generated sound. A signal generating means, a generated sound signal synthesizing means for synthesizing the generated sound original signal as a generated sound signal by an adaptive filter, and a characteristic selected by an occupant to at least one of the generated sound original signal generating means and the generated sound signal synthesizing means. And a sound source for generating a sound from the generated sound signal.

According to a second aspect of the present invention, there is provided a vehicle interior sound control device, comprising: a generated sound original signal generating means for detecting an engine rotation signal to generate an original signal of the generated sound; And a sound characteristic setting means for setting a characteristic selected by an occupant in at least one of the generated sound original signal generating means and the generated sound signal synthesizing means. A canceling sound source signal generating means for detecting and processing an engine rotation signal to generate a canceling sound original signal, and a canceling sound for synthesizing the canceling sound original signal as a canceling sound signal by an adaptive filter. Signal synthesis means, error signal detection means for detecting a noise reduction state at a listening point as an error signal, and a filter of the adaptive filter based on the error signal and the canceling sound original signal. A canceling sound control unit having filter coefficient updating means for updating a filter coefficient, and generating a sound source that generates sound from either the generated sound signal from the generated sound control unit or the canceling sound signal from the canceling sound control unit. It is provided.

[0010] Further, according to a third aspect of the present invention, in the vehicle interior sound control apparatus according to the first or second aspect, the generated sound original signal generating means includes acceleration / deceleration of engine rotation. The generated original signal is changed according to the state.

According to a fourth aspect of the present invention, there is provided a vehicle interior sound control apparatus according to any one of the first, second, and third aspects, wherein the generated sound signal synthesizing means is adapted to the adaptive sound generation means. The filter is formed to have a filter coefficient portion that expresses a transfer characteristic of sound in the vehicle cabin and a filter coefficient portion that performs a plurality of tone color adjustments.

According to a fifth aspect of the present invention, there is provided a vehicle interior sound control apparatus according to any one of the first, second, third and fourth aspects, wherein the sound characteristic setting means is provided. And at least one of the waveform and the level of the original signal generated by the generated sound original signal generating means in accordance with the selection of the occupant.

According to a sixth aspect of the present invention, there is provided a vehicle interior noise control apparatus according to any one of the first, second, third, fourth and fifth aspects. Variably sets the number of taps of the filter coefficient, adjusts the value of the filter gain, and increases or decreases the level of the original signal for the adaptive filter of the generated sound signal synthesizing means according to the occupant's selection. That is, at least one of setting the cycle of the original signal variably, and selectively setting a specific filter coefficient from a plurality of filter coefficients stored in advance.

[0014] The vehicle interior sound control device according to claim 1 is
The characteristic selected by the occupant is set in at least one of the generated sound original signal generating means and the generated sound signal synthesizing means by the sound characteristic setting means. The generated sound original signal generating means detects and processes the rotation signal of the engine to generate an original signal of the generated sound, and the generated sound signal synthesizing means converts the generated sound original signal into a generated sound signal by an adaptive filter. The sound is synthesized and the sound source generates sound based on the generated sound signal.

Further, in the vehicle interior sound control apparatus according to the second aspect, when the generated sound is reproduced and generated by the generated sound signal from the generated sound control section from the sound source, the generated sound original signal is generated by the sound characteristic setting means. The characteristic selected by the occupant is set in at least one of the generating means and the generated sound signal synthesizing means, and the generated sound original signal generating means detects the engine rotation signal and generates the generated sound original signal. The generated sound signal synthesizing means synthesizes the generated sound original signal as a generated sound signal by an adaptive filter, and the sound source generates a sound based on the generated sound signal. On the other hand, when the canceling sound for the vehicle interior noise due to the engine sound is reproduced and generated by the canceling sound signal from the canceling sound control unit from the sound source, the engine rotation signal is detected and processed by the canceling sound original signal generating means. Is generated by the cancellation sound signal synthesizing means, and the cancellation sound original signal is synthesized as a cancellation sound signal by an adaptive filter, and the sound source generates a sound based on the cancellation sound signal.
Then, the noise reduction state at the listening point is detected as an error signal by the error signal detection means, and the filter coefficient of the adaptive filter is updated based on the error signal and the cancellation original signal by the filter coefficient update means.

Further, in the vehicle interior sound control device according to the third aspect of the present invention, in the vehicle interior sound control device according to the first or second aspect, the generated sound original signal generation means may be in an acceleration / deceleration state of the engine rotation. The generated original signal is changed accordingly.

According to a fourth aspect of the present invention, in the vehicle interior sound control apparatus according to any one of the first, second, and third aspects, the signal is input to the generated sound signal synthesizing means. The generated sound original signal is convoluted with a filter coefficient portion of an adaptive filter that expresses the transfer characteristics of the sound in the cabin, and further convolved with a filter coefficient portion of the adaptive filter that performs a plurality of tone color adjustments and output. .

According to a fifth aspect of the present invention, there is provided a vehicle interior sound control apparatus according to any one of the first, second, third, and fourth aspects, wherein the sound characteristic setting means includes: And variably setting at least one of the waveform and the level of the original signal generated by the generated sound original signal generating means in accordance with the selection of the occupant.

According to a sixth aspect of the present invention, in the vehicle interior sound control apparatus according to any one of the first, second, third, fourth and fifth aspects, the sound characteristic setting means is provided. For the adaptive filter of the generated sound signal synthesizing means according to the selection of the occupant, variably setting the number of taps of the filter coefficient, adjusting the value of the filter gain,
At least one of increasing or decreasing the level of the original signal, variably setting the period of the original signal, and selectively setting a specific filter coefficient from a plurality of filter coefficients stored in advance is executed. I do.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a system schematic diagram of a vehicle interior sound control device,
FIG. 2 is an explanatory diagram of signal conversion in a generated sound original signal generation determining unit,
FIG. 3 is an explanatory diagram of signal conversion by an adaptive filter.

In FIG. 1, reference numeral 1 denotes a four-cycle engine, and an ignition pulse signal (Ig pulse signal) to an ignition coil (not shown) of the engine 1 is input to a vehicle interior sound control unit 2. I have.

A switch section for audio, air conditioner, etc. in the vehicle compartment is provided with a characteristic selecting section 3 for the sound generated by the vehicle interior sound control section 2. By operating the characteristic selecting section 3, the generated sound can be adjusted and selected.

Further, the vehicle interior sound control unit 2 is provided in the vehicle interior.
A speaker 4 is provided as a sound source for generating a sound by reproducing a signal from the A / D converter via a D / A converter, a filter circuit, and an amplifier circuit (not shown).

The cabin sound control section 2 is mainly composed of a generated sound original signal generation section 5, a generated sound signal synthesis section 6, and a sound characteristic setting section 7. The generated sound original signal is input to the generated sound original signal generation unit 5, the generated sound original signal is generated based on the Ig pulse signal, and the generated sound original signal is output to the generated sound signal synthesis unit 6. The generated sound original signal is synthesized as a generated sound signal by the section 6, and the generated sound signal is output to the speaker 4 via a D / A converter, a filter circuit, and an amplifier circuit to generate a generated sound. ing.

The signal from the sound characteristic selecting section 3 is
The sound characteristic setting unit 7 inputs the sound characteristic setting unit 7 so that the generated sound original signal generation unit 5 and the generated sound signal synthesis unit 6 have the characteristics selected by the occupant in the sound characteristic selection unit 3. Each characteristic is set as described above.

That is, the generated sound original signal generating section 5 is a function as a generated sound original signal generating means, and mainly includes a generated sound original signal generation determining section 5a and an acceleration / deceleration determining section 5b.

The acceleration / deceleration determination unit 5b determines whether the input Ig
The pulse signal is counted, and the signal level of the generated sound original signal generated by the generated sound original signal generation determining unit 5a is increased or decreased according to the count value. In the first embodiment of the present invention, the level of the generated sound original signal is set to increase as the count value increases, that is, as the engine rotation accelerates greatly.

Further, the generated sound original signal generation determining unit 5a
As shown in FIG. 2, an input Ig pulse is shaped into a predetermined waveform, for example, a staircase wave gradually attenuating to a low level, and a signal synchronized with engine rotation is output as a generated sound original signal. Has become. In addition, the signal from the sound characteristic setting unit 7 enables the signal form other than the staircase wave and the increase / decrease setting of the signal level.

The generated sound signal synthesizing section 6 serves as generated sound signal synthesizing means, and includes a first adaptive filter 6a having a first coefficient section and a second adaptive filter 6b having a second coefficient section. It has two stages.

As shown in FIG. 3, the first coefficient part of the first adaptive filter 6a has a filter coefficient that expresses the sound transmission characteristic of the vehicle cabin determined in advance by experiments such as system identification. The number of taps is set to be variable by the sound characteristic setting unit 7. For example, when the occupant operates the sound characteristic setting unit 7 to increase the reverberation sound,
The number of taps of the set filter coefficient is from 150 to 160
, Or increased to 200.

The second adaptive filter 6b has a second
In the coefficient section, a filter coefficient for further adding a timbre to the signal convolved and summed by the first coefficient section is set by the sound characteristic setting section 7. Thus, a specific filter coefficient is selected and set according to the occupant's preference from a plurality of filter coefficients obtained in advance by desk calculation or the like.

That is, the sound characteristic setting section 7 is a sound characteristic setting section, and has the above-mentioned functions, so that the sound characteristic determining section 7a, the impulse response selecting section 7b, the impulse response data storage section 7c, the additional characteristic It has a selection unit 7d and an additional characteristic data storage unit 7e.

The sound characteristic determining section 7a receives the signal from the sound characteristic selecting section 3 and sets the signal form other than the staircase wave and increases / decreases the signal level to the generated sound original signal generation determining section 5a. In addition to outputting a signal, a signal is output to the impulse response selector 7b and the additional characteristic selector 7d.

The impulse response selection section 7b stores a plurality of filter coefficients representing the transmission characteristics of the sound in the vehicle cabin determined in advance by experiments such as system identification based on the signal from the sound characteristic determination section 7a. An appropriate filter coefficient is selected from the impulse response data storage unit 7c thus determined, the number of taps is determined, and the tap number is set in the first coefficient unit of the first adaptive filter 6a.

Further, the additional characteristic selecting section 7d stores, on the basis of the signal from the sound characteristic determining section 7a, a plurality of filter coefficients for expressing a timbre previously calculated by a desk calculation or the like. An appropriate filter coefficient is selected from the storage section 7e, and is set in the second coefficient section of the second adaptive filter 6b.

The sound characteristic setting section 7 may set one of the characteristics of the generated sound original signal generating section 5 and the generated sound signal synthesizing section 6. The sound characteristic setting unit 7
The tone color setting for the second adaptive filter 6b of the generated sound signal synthesizing unit 6 by adjusting the filter gain by increasing or decreasing the central value of the signal from the first adaptive filter 6a, The level may be increased or decreased, the cycle of the signal may be changed, or a combination of these may be performed in various ways.

If the filter coefficient set in the generated sound signal synthesizing section 6 can be set to a characteristic other than those described above, for example, a sound transmission characteristic of a vehicle interior of another vehicle can be set.
It can express completely different sounds.

Next, the operation of the above configuration will be described. When the engine 1 is operated, the Ig pulse signal to the ignition coil is transmitted to the generated sound original signal generation unit 5 of the vehicle interior sound control unit 2.
Is input to

The Ig pulse signal is input to a generated sound original signal generation determining unit 5a and an acceleration / deceleration determining unit 5b of a generated sound original signal generating unit 5 of the vehicle interior sound control unit 2. The input Ig pulse signal is counted, and a signal is output to the generated sound original signal generation determining unit 5a so that the larger the count value, that is, the higher the engine rotation, the higher the level of the generated sound original signal. .

The Ig pulse signal input to the generated sound original signal generation determining unit 5a is a predetermined waveform having a predetermined level based on the signal from the acceleration / deceleration determining unit 5b and the signal from the sound characteristic setting unit 7. For example, the waveform is shaped into a staircase wave that gradually attenuates to a low level, and is output as a generated sound original signal synchronized with engine rotation.

The generated sound original signal is generated by the generated sound signal synthesizing unit 6.
First, the first adaptive filter 6a performs convolution multiply-accumulation with a first coefficient section in which a filter coefficient representing a sound transmission characteristic of the vehicle compartment is set, and then a second adaptive filter 6a The adaptive filter 6b performs convolution product-sum with a second coefficient section in which a filter coefficient for adding a tone color is set, and outputs the result.

The signal from the generated sound signal synthesizer 6 is D
A comfortable sound is generated from the speaker 4 via the / A converter, the filter circuit and the amplifier circuit.

When the occupant makes the generated sound different,
The sound characteristic selection unit 3 is operated, and the vehicle interior sound control unit 2 is operated.
The necessary signal is input to the sound characteristic setting unit 7 of the first embodiment.

This signal is input to the sound characteristic determining section 7a of the sound characteristic setting section 7, and the necessary signal from the sound characteristic determining section 7a is converted to the generated sound original signal of the generated sound original signal generating section 5. It is input to the generation determining unit 5a, the impulse response selecting unit 7b of the sound characteristic setting unit 7, or the additional characteristic selecting unit 7d.

That is, the sound characteristic determining section 7a receives the signal from the sound characteristic selecting section 3 and instructs the generated sound original signal generation determining section 5a other than the staircase wave of the generated sound original signal to be generated. And outputs an increase / decrease signal of the signal level.

In addition, the sound characteristic determination unit 7a supplies the impulse response selection unit 7b with a plurality of filter coefficients expressing the transmission characteristics of the sound in the vehicle cabin determined in advance by experiments such as system identification. An appropriate filter coefficient is selected from the stored impulse response data storage section 7c, the number of taps is determined, and a signal is output so as to be set in the first coefficient section of the first adaptive filter 6a.

The sound characteristic determining section 7a is provided with an additional characteristic data storing section in which a plurality of filter coefficients for expressing the timbre previously determined by a desk calculation or the like are stored for the additional characteristic selecting section 7d. 7e, an appropriate filter coefficient is selected, and a signal is output so as to be set in the second coefficient section of the second adaptive filter 6b.

Therefore, the generated sound changed according to the occupant's preference is generated from the speaker 4.

As described above, according to the first embodiment of the present invention, it is possible to make the engine sound various comfortable sounds according to the occupant's preference, and to realize a comfortable cabin space for the occupant. it can.

Further, since the system generates a comfortable sound by converting a signal based on the engine sound, it is also provided with a vehicle interior noise reduction device using an LMS algorithm for reducing vibration noise caused by an engine in the vehicle interior based on the engine sound. Cheap.

FIGS. 4 and 5 show a second embodiment of the present invention. FIG. 4 is a schematic diagram of a system of a vehicle interior sound control device, and FIG. 5 is an illustration of signal conversion in a canceling sound original signal generation unit. FIG. In the second embodiment of the present invention, the vehicle interior sound control unit is configured to generate a comfortable sound based on the engine sound positively by a generated sound control unit and a cancellation noise that reduces vibration noise by an engine in the vehicle interior. And a control unit, which are selectively usable.

That is, in FIG. 4, reference numeral 10 denotes a system selection unit, and reference numeral 11 denotes a vehicle interior sound control unit. An Ig pulse signal to the engine 1 is input to the system selection unit 10. From the vehicle interior sound controller 11.

The operation section (not shown) of the system selecting section 10 is provided on a switch panel portion of an audio system, an air conditioner, or the like in a vehicle compartment, and a mode for generating a comfortable sound based on the engine sound by an occupant. It is possible to select a mode for reducing vehicle interior noise due to sound.

The vehicle interior sound control section 11 is composed of a generated sound control section 11a and a cancellation sound control section 11b. When the system selection section 10 is set to the comfortable sound generation mode, the Ig pulse signal is output. It is input to the generated sound control unit 11a,
When the vehicle interior noise reduction mode is set, an Ig pulse signal is input to the cancellation sound control unit 11b.

The generated sound control section 11a has substantially the same configuration as the vehicle interior sound control section 2 described in the first embodiment of the present invention, and a description thereof will be omitted.

The canceling sound control section 11b mainly includes a canceling sound original signal generating section 12, an adaptive filter 13, a speaker / microphone compensating section 14, and an LMS calculating section 15.

The Ig pulse signal from the system selecting section 10 is input to the canceling sound original signal generating section 12 as the canceling sound original signal generating means.
As shown in FIG. 5, the Ig pulse signal input to the controller is a signal having a frequency of 0.5 × n (n: an integer) order component of the engine rotation in one pulse in two rotations of the engine in synchronization with the rotation of the engine. Is shaped and decimated into
The signal is input to the adaptive filter 13 and the speaker / microphone compensator 14.

The vibration noise related to the four-cycle engine is one cycle of two revolutions of the engine in order for the engine 1 to complete four strokes of suction, compression, explosion, and exhaust in two revolutions (720 ° C. A). In the frequency domain, a 0.5th-order component of engine rotation is used as a fundamental wave, and the spectrum is mainly composed of higher-order components (0.5 ×
n (n: integer) order component). Therefore, by shaping and processing the Ig pulse signal as described above, it is possible to obtain a cancellation sound original signal having a very high correlation with the vibration noise to be silenced.

Further, the adaptive filter 13 is provided with the LM
FIR (Finite Imp) as cancellation sound signal synthesizing means having a filter coefficient W (n) that can be updated by the S operation unit 15
ulseResponse) filter, which is formed with a predetermined number of taps (for example, 512 taps). The canceling sound original signal input to the adaptive filter 13 is convolved with the filter coefficient W (n) and summed up and output as a canceling sound signal. The D / A converter, the filter circuit, and the amplifier circuit (FIG. (Not shown), a canceling sound is generated from the speaker 4.

In the vicinity of the listening point in the passenger compartment, for example, in the headrest portion of the driver's seat, a microphone 16 is provided as an error signal detecting means for detecting the noise reduction state at the listening point as an error signal. An error signal (a signal indicating the result of interference between the cancellation sound and the engine-related vibration noise) indicating the noise reduction state detected by the amplifier circuit,
Filter circuit and A / D converter (both not shown)
Is input to the LMS calculation unit 15 via the.

On the other hand, the speaker / microphone compensator 14
, The speaker-to-microphone transfer characteristic CMN is set in advance by approximating it with a finite impulse response (as a compensation coefficient CMN0). And outputs a signal to the LMS operation unit 15.

The LMS calculating section 15 serves as a filter coefficient updating means, and cancels out the signal from the microphone 16 and the canceling sound (convoluted sum of products) compensated by the speaker / microphone compensating section 14. From the original signal, the well-known L
The correction amount of the filter coefficient W (n) of the adaptive filter 13 is obtained by the MS algorithm, and the filter coefficient W (n) is updated.

Here, the updated i-th filter coefficient is Wi (n + 1), the updated i-th filter coefficient is Wi (n), the update rate (step size) is μ, and the LMS calculation unit 15 The input signal from the microphone 16 is E (n), and the j-th coefficient of the speaker / microphone compensation coefficient CMN0 between the microphone channel M and the speaker N is the input signal represented by CMjN0, X (n). Assuming that the value i + j before is X (nij) and the number of taps of the compensation coefficient CMN0 is J, the update of the filter coefficient of the adaptive filter is Becomes

In FIG. 4, reference character C indicates a vehicle body transmission characteristic with respect to vibration noise of the engine 1.

Next, the operation of the embodiment of the present invention having the above configuration will be described. First, when the occupant operates the system selection unit 10 to select a mode for generating a comfortable sound based on the engine sound, the system control unit 10 outputs the Ig pulse signal to the sound generated by the vehicle interior sound control unit 11. It is input to the control unit 11a.

Further, the Ig pulse signal is input to a generated sound original signal generation section 5 of the generated sound control section 11a, and the generated sound original signal generation section 5 generates a generated sound original signal based on the Ig pulse signal. The generated sound signal synthesizing section 6 synthesizes the generated sound original signal as a generated sound signal, and the generated sound signal is passed through a D / A converter, a filter circuit, and an amplifier circuit. The generated sound is output to the speaker 4 and reproduced and generated.

If the occupant wants to generate a different sound, the sound characteristic selecting section 3 of the switch panel portion of the audio and air conditioner in the passenger compartment is operated, and the sound characteristic setting section of the generated sound control section 11a is operated. 7, necessary signals are inputted.
The sound characteristic setting unit 7 allows the generated sound original signal generation unit 5
Each characteristic is set so that the generated sound signal synthesizing unit 6 has the characteristic selected by the occupant in the sound characteristic selecting unit 3. The details of the operation of the generated sound control unit 11a are substantially the same as those of the first embodiment of the present invention, and will not be described.

Next, when the occupant operates the system selecting section 10 to select a mode for reducing the vehicle interior noise due to the engine sound, the system selecting section 10 causes the system selecting section 10 to cancel out the vehicle interior sound control section 11. Sound control unit 11b
Is input to

In this case, the vibration noise of the engine is transmitted from the engine 1 to a not-shown mount or the like and becomes a vehicle interior sound, and the sound of intake and exhaust is also transmitted to the vehicle interior. In the frequency domain, each is mainly constituted by a frequency spectrum of a 0.5 × n (n: integer) order component, and reaches the listening point by being multiplied by the vehicle body transfer characteristic C for each vibration source.

On the other hand, the Ig pulse signal to the ignition coil of the engine 1 is input to the canceling sound source signal generating unit 12 of the canceling sound control unit 11b. 0.5 of rotation
× n (n: integer) Formed into a signal consisting of the frequency of the next component
After being decimated, the adaptive filter 13,
Output to the speaker / microphone compensator 14.

The canceling sound original signal input to the adaptive filter 13 has a filter coefficient W (n)
Is output as a cancellation sound signal for canceling the vibration noise, and is output to the speaker 4 via the D / A converter, the filter circuit, and the amplifier circuit, and the vibration noise at the listening point from the speaker 4 is output. Is output as a canceling sound for. At this time, the canceling sound reaches the listening point by receiving the speaker / microphone transfer characteristic CMN.

For this reason, at the listening point, the vibration noise related to the engine and the canceling sound interfere with each other to reduce the vibration noise, and at the same time, the microphone 16 disposed near the listening point causes The result of the interference between the vibration noise and the cancellation noise is detected, and is input as an error signal to the LMS calculation unit 15 via an amplifier circuit, a filter circuit, and an A / D converter.

The canceling sound original signal input to the loudspeaker / microphone compensator 14 is multiplied (convoluted, summed up) by the compensation coefficient CMN0 and compensated and output to the LMS calculator 15.

The LMS calculation section 15 uses the error signal from the microphone 16 and the canceling sound original signal compensated by the speaker / microphone compensation section 14 to obtain a well-known LM signal.
The correction amount of the filter coefficient W (n) of the adaptive filter 13 is obtained by the S algorithm, and the filter coefficient W (n) is updated.

As described above, according to the second embodiment of the present invention, the occupant can select his / her favorite comfortable sound and the reduction of engine-related vehicle interior noise in accordance with the situation, thereby providing a more comfortable vehicle. Drive can be done.

Further, the system for generating a comfortable sound has excellent effects as described in the first embodiment of the present invention, and also uses the LMS algorithm for forming a sound based on a signal to the engine to produce a vehicle interior noise. It can be easily installed together with the reduction system, and by sharing many parts, it is possible to reduce the number of parts, reduce the size and weight, and reduce the cost of the vehicle interior sound control device itself.

The generated sound original signal in the first and second embodiments of the present invention and the canceling sound original signal in the second embodiment of the present invention are configured to be generated using an Ig pulse signal. Alternatively, similar signals (for example, fuel injection pulse Ti, etc.) related to other engines may be used.

In the second embodiment of the present invention, an example in which the vehicle interior noise reduction system uses the LMS algorithm of one channel (one microphone and one speaker) has been described. The present invention is also applicable to a vehicle interior noise reduction device (for example, a device such as four microphones and four speakers) using the expanded MEFX-LMS algorithm.

[0079]

As described above, according to the present invention, a comfortable engine sound according to the occupant's preference and a sound synchronized with the engine sound can be generated, and a comfortable cabin space for the occupant can be formed. . In addition, a vehicle interior noise reduction device can be easily installed, and by installing the vehicle interior noise reduction device, the occupant can generate his / her favorite comfortable sound and reduce engine-related vehicle interior noise according to the situation. Can be selected, and a more comfortable drive can be performed.

[Brief description of the drawings]

FIG. 1 is a system schematic diagram of a vehicle interior sound control device according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram of signal conversion in a generated sound original signal generation determining unit according to the first embodiment of the present invention;

FIG. 3 is an explanatory diagram of signal conversion by an adaptive filter according to the first embodiment of the present invention;

FIG. 4 is a system schematic diagram of a vehicle interior sound control device according to a second embodiment of the present invention;

FIG. 5 is an explanatory diagram of signal conversion in a cancellation sound original signal generation unit according to a second embodiment of the present invention.

[Description of Signs] 1 engine 2 vehicle interior sound control unit 3 sound characteristic selection unit 4 speaker (sound source) 5 generated sound original signal generation unit (generated sound original signal generation means) 5a generated sound original signal generation determination unit 5b acceleration / deceleration determination Unit 6 Generated sound signal synthesis unit (generated sound signal synthesis unit) 6a First adaptive filter 6b Second adaptive filter 7 Sound characteristic setting unit (Sound characteristic setting unit) 7a Sound characteristic determination unit 7b Impulse response selection unit 7c Impulse response Data storage unit 7d Additional characteristic selection unit 7e Additional characteristic data storage unit

Claims (6)

[Claims] A generated sound original signal generating means for detecting an engine rotation signal to generate an original signal of a generated sound, and a generated sound signal synthesizing means for synthesizing the generated sound original signal as a generated sound signal by an adaptive filter. Sound characteristic setting means for setting a characteristic selected by an occupant in at least one of the generated sound original signal generating means and the generated sound signal synthesizing means, and a sound source for generating a sound from the generated sound signal. Characteristic vehicle interior sound control device. 2. A generated sound original signal generating means for detecting an engine rotation signal to generate a generated sound original signal, and a generated sound signal synthesizing means for synthesizing the generated sound original signal as a generated sound signal by an adaptive filter. At least one of the generated sound original signal generating means and the generated sound signal synthesizing means having a sound characteristic setting means for setting a characteristic selected by an occupant; A canceling sound original signal generating means for generating an original signal of the canceling sound, a canceling sound synthesizing means for synthesizing the canceling sound original signal as a canceling sound signal by an adaptive filter, and a noise reduction state at a listening point as an error signal. An error signal detecting means for detecting, and a filter coefficient updating means for updating a filter coefficient of the adaptive filter based on the error signal and the canceling sound original signal. A vehicle interior sound control device comprising: a sound killing control unit; and a sound source that generates a sound from one of a generated sound signal from the generated sound control unit and a canceled sound signal from the canceled sound control unit. . 3. The vehicle interior sound control device according to claim 1, wherein said generated sound original signal generating means changes an original signal generated according to an acceleration / deceleration state of engine rotation. 4. The adaptive filter of the generated sound signal synthesizing means, wherein the adaptive filter includes a filter coefficient portion expressing a transfer characteristic of a sound in a vehicle cabin and a filter coefficient portion performing a plurality of tone color adjustments. The vehicle interior sound control device according to any one of claims 1, 2, and 3. 5. The sound characteristic setting means variably sets at least one of a waveform and a level of the original signal generated by the generated sound original signal generating means in accordance with an occupant's selection. Item 5. The vehicle interior sound control device according to any one of Items 1, 2, 3, and 4. 6. The sound characteristic setting means variably sets the number of taps of a filter coefficient with respect to the adaptive filter of the generated sound signal synthesizing means according to a passenger selection, and adjusts a value of a filter gain. At least one of increasing and decreasing the level of the original signal, variably setting the period of the original signal, and selectively setting a specific filter coefficient from a plurality of filter coefficients stored in advance. 3. The method according to claim 1, wherein
6. The vehicle interior sound control device according to any one of 5.