JPH03169763A - Device for reducing noise in interior of car - Google Patents
Device for reducing noise in interior of carInfo
- Publication number
- JPH03169763A JPH03169763A JP1311898A JP31189889A JPH03169763A JP H03169763 A JPH03169763 A JP H03169763A JP 1311898 A JP1311898 A JP 1311898A JP 31189889 A JP31189889 A JP 31189889A JP H03169763 A JPH03169763 A JP H03169763A
- Authority
- JP
- Japan
- Prior art keywords
- noise
- engine
- car
- interior
- vibration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003044 adaptive effect Effects 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 7
- 210000005069 ears Anatomy 0.000 abstract description 3
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 230000006870 function Effects 0.000 description 16
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000004880 explosion Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000002945 steepest descent method Methods 0.000 description 1
Landscapes
- Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は車室内騒音の低減装置に関し、特に周期的な音
源を有する自動車等の車室閉空間内の低周波の騒音をア
クティブに低減する装置に関するものである．
〔従来の技術〕
自動車等の車室内の騒音は、閉空間を形或する車室が一
定の条件下で共振現象を起こすことに因るものであり、
その原因たる起振力はエンジンの回転振動威分等による
ものと考えられている．このような騒音を低減させるた
めの対策として当初採られていた手段は、パッシブ（受
動的）なものであり、例えば振動源であるエンジン系に
対して結合剛性を向上させ、伝達系に対しては各マウン
トのチューニングを行い、車室内の発音体に対してはパ
ネル剛性アップを図り、更に共振対策として、マスダン
パー、ダイナミックダンパー等を共振部分に施していた
．
このようなパッシブな手段では、コストの上昇及び重量
の増大を招くと共に、その効果は不十分なものであった
．
一方、このような車室内騒音は、４気筒エンジンの場合
、クランク軸１回転の２回爆発威分で、所謂エンジン回
転２次成分と称しているエンジン回転次数或分が主要因
と考えられており、このような要因で引き起こされるこ
もり音をアクティブに低減しようとする従来技術として
、特開昭５９９６９９号公報や実開昭６２−１２７０５
１号公報等が既に提案されている。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vehicle interior noise reduction device, and particularly to a device for actively reducing low-frequency noise in a closed space of a vehicle such as an automobile that has a periodic sound source. This is related to equipment. [Prior Art] Noise inside a vehicle such as an automobile is caused by the resonance phenomenon that occurs in the vehicle interior, which forms a closed space, under certain conditions.
The cause of this is thought to be the vibrational force of the engine's rotation. The measures initially taken to reduce such noise were passive, such as improving the coupling rigidity of the engine system, which is the source of vibration, and improving the coupling rigidity of the transmission system. The company tuned each mount, increased the panel rigidity of the sounding element inside the vehicle, and also installed mass dampers, dynamic dampers, etc. on the resonant parts to prevent resonance. Such passive means increased cost and weight, and were insufficiently effective. On the other hand, in the case of a 4-cylinder engine, such cabin noise is caused by two explosions per revolution of the crankshaft, and is thought to be mainly caused by the engine rotational order, which is the so-called secondary engine rotational component. Conventional techniques that attempt to actively reduce the muffled sound caused by such factors include Japanese Patent Application Laid-Open No. 599699 and Japanese Utility Model Application No. 62-12705.
Publication No. 1 etc. have already been proposed.
これらの従来技術では、エンジン回転２次成分としてイ
グニッションパルスを検出し、このパルス信号を種々処
理し、車室内のドライバの受詫点で観測される騒音の各
周波数成分（回転次数戒分）の逆位相で且つ大きさが騒
音成分と同じになる音をスピーカから別途付加すること
により、干渉効果で受聰点での騒音レベルを相殺・低減
している．〔発明が解決しようとする課題〕
しかしながら、上記の従来例は、車室内騒音の内、エン
ジン回転２次威分に起因するこもり音のみを低減するた
めの装置であり、エンジンの爆発（回転）による回転２
次成分以外の回転次数成分（爆発次数威分）に起因する
騒音威分が存在しても除去することができず、騒音低減
が最適なものとならない。In these conventional technologies, the ignition pulse is detected as a secondary component of engine rotation, this pulse signal is processed in various ways, and each frequency component (rotational order division) of the noise observed at the driver's reception point in the vehicle interior is detected. By separately adding sound from a speaker that is in opposite phase and has the same magnitude as the noise component, the interference effect cancels out and reduces the noise level at the listening point. [Problems to be Solved by the Invention] However, the above-mentioned conventional example is a device for reducing only the muffled noise caused by the secondary influence of engine rotation among the noise inside the vehicle, and the explosion (rotation) of the engine Rotation by 2
Even if there is a noise component caused by a rotation order component (explosion order component) other than the next component, it cannot be removed, and the noise reduction will not be optimal.
また、車両のエンジン系、マウント系、電気系等の経時
的な変化や、電気信号系の温度特性の変化、更には乗員
の変化、車室内温度等の変化、及び何らかの外乱の侵入
等に絶えず対処することができないか、又は制御の即応
性が得られないという問題点があった。In addition, it is constantly affected by changes over time in the vehicle's engine system, mounting system, electrical system, etc., changes in the temperature characteristics of the electrical signal system, changes in the number of occupants, changes in the cabin temperature, etc., and the intrusion of some external disturbance. There was a problem that it was impossible to deal with the problem or the immediate response of the control could not be obtained.
従って、本発明は、車室内におけるエンジン回転２次成
分に起因するこもり音だけでなくそれ以外の騒音威分も
併せて除去でき且つ車両条件の種々の変化に即応できる
簡易な装置を実現することを目的とする。Therefore, it is an object of the present invention to realize a simple device that can eliminate not only the muffled noise caused by the secondary component of engine rotation in the vehicle interior, but also other noise components, and that can immediately respond to various changes in vehicle conditions. With the goal.
上記の課題を解決するため、本発明に係る車室内騒音の
低減装置では、エンジンの振動検出手段と、該検出手段
の検出信号から車室の振動系の耳元までの伝達関数の逆
伝達関数を同定する適応型コントローラと、該コントロ
ーラの出力信号を車室内に出力するスピーカと、該スピ
ーカ出力を含む全車室内騒音を検出するマイクロホンと
を備え、該コントローラが該マイクロホンの入力が最小
になるように該スピーカを制御するようにしている。In order to solve the above problems, the vehicle interior noise reduction device according to the present invention includes an engine vibration detection means and an inverse transfer function of a transfer function from the detection signal of the detection means to the ears of the vibration system of the vehicle interior. an adaptive controller for identifying the noise, a speaker for outputting an output signal of the controller into the vehicle interior, and a microphone for detecting all vehicle interior noise including the output of the speaker, and the controller is configured so that the input of the microphone is minimized. The speaker is controlled.
本発明に係る車室内騒音の低減装置では、第ｌ図の等価
ブロック図に示すように、Ｇはエンジンの振動によって
励起される車室内振動系の総合した伝達関数であって、
エンジンの振動に基づいてエンジン・マウントによる伝
達関数（ＭＴＧ）、トルク・ロッドによる伝達関数、キ
ャブ・マウントによる伝達関数等から戒っており、この
伝達関数Ｇによりエンジン振動が車室内空間伝達路によ
って耳元で車室内騒音Ｙ （ｎ）に変換された形で観測
されるものである．
この場合、エンジン振動自体はエンジン回転２次戒分に
よるものであるが、耳元で観測される車室内騒音Ｙ （
ｎ）は伝達関数Ｇによりエンジン回転２次戒分以外の威
分をも含むものとなっている．この伝達関数Ｇは未知の
値であり、コントローラ５によりこの伝達関数の逆伝達
関数Ｇ−’を同定するが、このコントローラ５はエンジ
ン振動検出手段により検出されたエンジン振動信号Ｘ
（ｎ）とマイクロホンからの出力信号ｅ （ｎ）とを常
に入力し、そして、これらの信号に基づいて周知のＬＭ
Ｓ（Ｌｅａｓｔ Ｍｅａｎ Ｓｑｕａｒｅ）法等により
フィルタ係数列Ｈを適応制御してスピーカ出力ｙ （ｎ
）を発生し、上記の車室内騒音Ｙ （ｎ）を相殺する．
そして、この適応的な動作を進めることによってスピー
カ出力によって相殺し切れなかった車室内騒音は徐々に
小さくなって行くこととなる．従って、本発明のように
適応型コントローラを用いれば、車室内のマイクロホン
に入力される情報のうちエンジン振動による検出信号の
全てが制御対象となり、エンジンの次数威分以外の騒音
をも相殺できるのでより完全な形で然も迅速に車室内騒
音の低減が図られる．
〔実 施 例〕
第２図は本発明に係る車室内騒音の低減装置の一実施例
を示したもので、１は車両の車室、２は自動車ｌのエン
ジン、３はエンジン２のエンジン振動を検出するセンサ
、４は車室内の騒音レベルを検出するマイクロホン、５
はセンサ３及び４の出力によりエンジンの振動で励起さ
れる車体の振動系の伝達関数の逆伝達関数を同定するコ
ントローラ、６は騒音を減少させる音を発生するスピー
カ、７はコントローラ５からの信号を増幅してスピーカ
６を駆動する増幅器である．尚、センサ３としてノック
センサを用いてもよい．
第３図は第２図に示したコントローラの一実施例を示し
たもので、この実施例では適応ディジタルフィルタで構
威されており、適応アルゴリズムとしては周知の最急降
下法や、学習同定法や、ＬＭＳ法等が挙げられるが、こ
こではＬＭＳ法を用いている．
また、ｎ個のＺ−１はエンジン振動Ｘ （ｎ）を各サン
プル毎に遅延させるための遅延素子を示し、ｎ個のｈ（
０）〜ｈ （ｎ−１）は各遅延素子Ｚ−１に対し乗算す
るためのフィルタ（タップ）係数であり、各フィルタ係
数はＬＭＳアルゴリズム、即ち、ｈ（＋＋１）＝ｈ（ｉ
）＋２ ｔｔ ｅ（ｎ）Ｘ（ｎ−ｉ）に従ってサンプル
毎に更新される．但し、ｉ＝０・・・ｎ．μはステップ
サイズである．そして、このようなフィルタ係数を各サ
ンプルのエンジン振動Ｘ （ｎ）に掛け且つ加算すると
いう畳み込み演算を行うことにより増幅器７を介してス
ピーカ６への出力信号ｙ （ｎ）が求められる．このス
ピーカ出力ｙ （ｎ）を、実際にドライバーの耳元で観
測される音圧Ｙ （ｎ）から差し引くことにより、マイ
クロホン４からの出力ｅ （ｎ） ＝ Ｙ （ｎ） −
ｙ （ｎ）が発生され、これに基づいて再びＬＭＳア
ルゴリズムによりフィルタ係数を更新すれば、徐々に車
室内の振動系の伝達関数Ｇの逆伝達関数Ｇ−１を同定し
て行くことができ、マイク出力ｅ （ｎ）を最小値に収
束させることができる．
尚、エンジン振動信号Ｘ （ｎ）がいつも平均値や自乗
平均値が時間的に変化しない定常信号であるとは限らな
いが、適切なサンプリング数とタップ数であれば過渡的
な状態でも制御を収束させることができる．
〔発明の効果〕
以上のように、本発明に係る車室内騒音の低減装置では
、適応型コントローラを用いてエンジン振動による耳元
までの車室内振動系の伝達関数の逆伝達関数をエンジン
振動信号とマイク出力とにより同定してスピーカにより
そのエンジン振動による車室内騒音を相殺するように構
威したので、第４図のエンジン回転次数比例解析図に示
すように、従来例を示す同図（ａ）に比べて、本発明に
よる同図（ｂ）の方がエンジン回転２次威分以外の威分
をも相殺していることが分かる．
従って、エンジンの爆発に起因する回転次数威分に対応
した複数の発振器を用いることも必要無く、また、点火
信号や着火タイミングを検出し、更に車両状態や車両外
部環境等に応じた補正（例えば実開昭６２−１２７０５
２号公報に示すような進角補正）をする必要も無くエン
ジンの回転によって制御すべき回転次数成分を全てを包
含した車室内騒音の低減を簡素化されたシステムで実現
することができる．
更にはエンジン振動そのものを検出して車室内騒音を低
減させているので、入力と出力との関係で制御が行われ
、振動伝達系の特性変化分をも含めた制御系となり、外
乱に強くロバスト性の高いシステムが構築できる効果が
ある．In the vehicle interior noise reduction device according to the present invention, as shown in the equivalent block diagram of FIG. 1, G is the overall transfer function of the vehicle interior vibration system excited by engine vibration,
Based on the vibration of the engine, the engine mount transfer function (MTG), the torque rod transfer function, the cab mount transfer function, etc. are used. This is what is observed near the ear in the form of cabin noise Y (n). In this case, the engine vibration itself is due to the second-order vibration of the engine rotation, but the cabin noise Y (
n) includes factors other than the quadratic engine speed due to the transfer function G. This transfer function G is an unknown value, and the controller 5 identifies the inverse transfer function G-' of this transfer function.
(n) and the output signal e (n) from the microphone are always input, and based on these signals, the well-known LM
The speaker output y (n
) to offset the above-mentioned cabin noise Y (n).
By proceeding with this adaptive operation, the interior noise that cannot be canceled out by the speaker output will gradually become smaller. Therefore, if an adaptive controller is used as in the present invention, all of the engine vibration detection signals among the information input to the microphone inside the vehicle are subject to control, and noise other than the engine order noise can also be canceled out. In-vehicle noise can be reduced more completely and quickly. [Embodiment] Fig. 2 shows an embodiment of the vehicle interior noise reduction device according to the present invention, in which 1 is the interior of the vehicle, 2 is the engine of the automobile 1, and 3 is the engine vibration of the engine 2. 4 is a microphone that detects the noise level inside the vehicle; 5 is a sensor that detects
6 is a controller that identifies the inverse transfer function of the transfer function of the vibration system of the vehicle body excited by engine vibration based on the outputs of sensors 3 and 4; 6 is a speaker that generates a sound to reduce noise; 7 is a signal from controller 5; This is an amplifier that amplifies and drives the speaker 6. Note that a knock sensor may be used as the sensor 3. FIG. 3 shows an example of the controller shown in FIG. 2. In this example, an adaptive digital filter is used, and adaptive algorithms include the well-known steepest descent method, learning identification method, etc. , LMS method, etc., but the LMS method is used here. In addition, n Z-1 designates delay elements for delaying engine vibration X (n) for each sample, and n h(
0) to h (n-1) are filter (tap) coefficients for multiplying each delay element Z-1, and each filter coefficient is determined by the LMS algorithm, that is, h(++1)=h(i
)+2 tt e(n) updated every sample according to X(ni). However, i=0...n. μ is the step size. Then, by performing a convolution operation in which each sample of engine vibration X (n) is multiplied by such a filter coefficient and added, an output signal y (n) to be output to the speaker 6 via the amplifier 7 is obtained. By subtracting this speaker output y (n) from the sound pressure Y (n) actually observed near the driver's ear, the output from the microphone 4 e (n) = Y (n) −
y (n) is generated and the filter coefficients are updated again using the LMS algorithm based on this, it is possible to gradually identify the inverse transfer function G-1 of the transfer function G of the vibration system in the vehicle interior. The microphone output e (n) can be converged to the minimum value. It should be noted that the engine vibration signal It can be converged. [Effects of the Invention] As described above, the vehicle interior noise reduction device according to the present invention uses an adaptive controller to convert the inverse transfer function of the transfer function of the vehicle interior vibration system up to the ear caused by engine vibration into an engine vibration signal. As shown in the engine rotation order proportional analysis diagram in Figure 4, the conventional example is shown in Figure 4 (a). It can be seen that, compared to the figure (b) according to the present invention, power components other than the engine rotation secondary power component are also canceled out. Therefore, there is no need to use multiple oscillators corresponding to the rotational order fluctuations caused by engine explosion, and it is also possible to detect the ignition signal and ignition timing, and to make corrections according to the vehicle condition, vehicle external environment, etc. Utsukai Showa 62-12705
There is no need for advance angle correction (as shown in Publication No. 2), and cabin noise reduction can be achieved with a simplified system that includes all rotational order components that should be controlled by engine rotation. Furthermore, since the engine vibration itself is detected to reduce cabin noise, control is performed based on the relationship between input and output, and the control system also takes into account changes in the characteristics of the vibration transmission system, making it highly resistant to external disturbances and robust. This has the effect of allowing you to build a system with high performance.
第１図は、本発明に係る車室内騒音の低減装置を原理的
に示したブロック図、
第２図は、本発明に係る車室内騒音の低減装置の一実施
例を示す概略構威図、
第３図は、本発明に用いられるコントローラの−実施例
を示した図、
第４図は、本発明の効果を示す回転次数比解析図、であ
る．FIG. 1 is a block diagram showing the principle of a vehicle interior noise reduction device according to the present invention; FIG. 2 is a schematic structural diagram showing an embodiment of a vehicle interior noise reduction device according to the present invention; Fig. 3 is a diagram showing an embodiment of the controller used in the present invention, and Fig. 4 is a rotational order ratio analysis diagram showing the effects of the present invention.
Claims (1)
車体の振動系の耳元までの伝達関数の逆伝達関数を同定
する適応型コントローラと、該コントローラの出力信号
を車室内に出力するスピーカと、該スピーカ出力を含む
全車室内騒音を検出するマイクロホンとを備え、該コン
トローラが該マイクロホンの入力が最小になるように該
スピーカを制御することを特徴とした車室内騒音の低減
装置。An engine vibration detection means, an adaptive controller that identifies an inverse transfer function of a transfer function from the detection signal of the detection means to the ear of the vibration system of the vehicle body, and a speaker that outputs an output signal of the controller into the vehicle interior; A vehicle interior noise reduction device comprising: a microphone that detects all vehicle interior noise including output from the speaker; and wherein the controller controls the speaker so that input to the microphone is minimized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1311898A JP2841585B2 (en) | 1989-11-30 | 1989-11-30 | Vehicle interior noise reduction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1311898A JP2841585B2 (en) | 1989-11-30 | 1989-11-30 | Vehicle interior noise reduction device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03169763A true JPH03169763A (en) | 1991-07-23 |
| JP2841585B2 JP2841585B2 (en) | 1998-12-24 |
Family
ID=18022745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1311898A Expired - Fee Related JP2841585B2 (en) | 1989-11-30 | 1989-11-30 | Vehicle interior noise reduction device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2841585B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100018500A1 (en) * | 2008-07-24 | 2010-01-28 | Honda Motor Co., Ltd. | Speed Dependent Knock Control |
| CN104296994A (en) * | 2014-09-22 | 2015-01-21 | 北京强度环境研究所 | Trial condition noise and vibration transmission test method |
| WO2017041284A1 (en) * | 2015-09-11 | 2017-03-16 | Harman International Industries, Incorporated | Noise reduction |
-
1989
- 1989-11-30 JP JP1311898A patent/JP2841585B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100018500A1 (en) * | 2008-07-24 | 2010-01-28 | Honda Motor Co., Ltd. | Speed Dependent Knock Control |
| US8291888B2 (en) * | 2008-07-24 | 2012-10-23 | Honda Motor Co., Ltd. | Speed dependent knock control |
| CN104296994A (en) * | 2014-09-22 | 2015-01-21 | 北京强度环境研究所 | Trial condition noise and vibration transmission test method |
| CN104296994B (en) * | 2014-09-22 | 2017-02-01 | 北京强度环境研究所 | Trial condition noise and vibration transmission test method |
| WO2017041284A1 (en) * | 2015-09-11 | 2017-03-16 | Harman International Industries, Incorporated | Noise reduction |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2841585B2 (en) | 1998-12-24 |
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