JPH0248045B2 - - Google Patents

Info

Publication number
JPH0248045B2
JPH0248045B2 JP57177214A JP17721482A JPH0248045B2 JP H0248045 B2 JPH0248045 B2 JP H0248045B2 JP 57177214 A JP57177214 A JP 57177214A JP 17721482 A JP17721482 A JP 17721482A JP H0248045 B2 JPH0248045 B2 JP H0248045B2
Authority
JP
Japan
Prior art keywords
knocking
vibration
bandwidth
bandpass filter
engine
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.)
Expired - Lifetime
Application number
JP57177214A
Other languages
Japanese (ja)
Other versions
JPS5965728A (en
Inventor
Ichiro Maki
Kenzo Miura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP57177214A priority Critical patent/JPS5965728A/en
Publication of JPS5965728A publication Critical patent/JPS5965728A/en
Publication of JPH0248045B2 publication Critical patent/JPH0248045B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
    • G01L23/22—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines
    • G01L23/221—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines for detecting or indicating knocks in internal combustion engines
    • G01L23/225—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid for detecting or indicating knocks in internal-combustion engines; Units comprising pressure-sensitive members combined with ignitors for firing internal-combustion engines for detecting or indicating knocks in internal combustion engines circuit arrangements therefor

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Testing Of Engines (AREA)

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、自動車などのエンジンにおけるノツ
キングを検知するノツキング検知装置に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a knocking detection device for detecting knocking in an engine of an automobile or the like.

従来例の構成とその問題点 自動車などのエンジンのノツキングを検知する
方式として、ノツキングに伴なうエンジン固有の
振動をとらえる方式が一般に行なわれている。Conventional configurations and their problems As a method for detecting knocking in an engine such as an automobile, a method that captures the vibration inherent in the engine accompanying knocking is generally used.

ノツキングに伴なうエンジン固有の振動は一般
的に６〜14KHzの範囲にあり、この振動を検知す
るセンサとしては、第１図に示すように共振周波
数が20KHz以上であり、ノツキングの固有周波数
に対する周波数特性がフラツトなセンサ、例えば
圧電型センサが用いられている。 The engine-specific vibration associated with knocking is generally in the range of 6 to 14 KHz, and a sensor that detects this vibration must have a resonant frequency of 20 KHz or higher, as shown in Figure 1, and is A sensor with flat frequency characteristics, such as a piezoelectric sensor, is used.

このセンサの出力信号を、ノツキングの固有周
波数は選択特性を持つバンドパスフイルタに入力
し、ノツキング固有の周波数を抽出することが行
なわている。 The output signal of this sensor is input to a bandpass filter having a characteristic of selecting the natural frequency of knocking, and the frequency peculiar to knocking is extracted.

第２図は従来のノツキング検知装置を示してい
る。以下にこの従来例の構成について第２図とと
もに説明する。第２図において、１はエンジン振
動を検出する振動ピツクアツプ、２は増幅器、３
はバンドパスフイルタ、４は比較器、５は平均化
回路、６は増幅器、７はノツキング判定出力端で
ある。 FIG. 2 shows a conventional knocking detection device. The configuration of this conventional example will be explained below with reference to FIG. 2. In Fig. 2, 1 is a vibration pickup for detecting engine vibration, 2 is an amplifier, and 3 is a vibration pickup for detecting engine vibration.
4 is a band pass filter, 4 is a comparator, 5 is an averaging circuit, 6 is an amplifier, and 7 is a knocking judgment output terminal.

上記従来例の動作について詳明する。第２図に
おいて、増幅器２は振動ピツクアツプ１の信号を
増幅する。この出力はバンドパスフイルタ３と平
均化回路５に入力され、バンドパスフイルタ３は
ノツキング特徴周波数を選択し帯域通過させる。
一方、平均化回路５は増幅器２の出力の平均値を
出し、この平均値出力は増幅器６で増幅される。
比較器４は、バンドパスフイルタ３と増幅器６の
出力レベルを比較し、バンドパスフイルタ３の出
力レベルの方が大きいとき、ノツキング判定出力
を出す。この様にしてノツキングを判定するの
が、従来の方式であつた。 The operation of the above conventional example will be explained in detail. In FIG. 2, an amplifier 2 amplifies the signal of the vibration pickup 1. In FIG. This output is input to a bandpass filter 3 and an averaging circuit 5, and the bandpass filter 3 selects the knocking characteristic frequency and passes it through the band.
On the other hand, the averaging circuit 5 outputs an average value of the output of the amplifier 2, and this average value output is amplified by the amplifier 6.
Comparator 4 compares the output levels of bandpass filter 3 and amplifier 6, and outputs a knocking determination output when the output level of bandpass filter 3 is higher. The conventional method was to determine knocking in this manner.

しかしながら、上記従来例においては、バンド
パスフイルタの中心周波数の帯域幅は一定値に設
定されていた。このため、帯域幅がせまければ、
選択性に秀れＳ／Ｎがよくなるが、一方信号の時
間的変化がはやい場合は、フイルタの時定数など
の関係で立上り、立下り時間が長くなり信号検出
が困難となり、逆に、バンドパスフイルタの帯域
幅が広ければ、信号の変化に対する追従性は良い
が選択性が悪くなる欠点があつた。 However, in the conventional example described above, the bandwidth of the center frequency of the bandpass filter was set to a constant value. Therefore, if the bandwidth is small,
It has excellent selectivity and improves S/N, but on the other hand, if the signal changes quickly over time, the rise and fall times will be longer due to the time constant of the filter, making signal detection difficult. If the filter has a wide bandwidth, it has good followability to signal changes, but has the disadvantage of poor selectivity.

このように、従来例では帯域幅が一定値である
ため、低速回転から高速回転までノツキング検知
を確実に行なうことがむずかしいものであつた。 As described above, in the conventional example, since the bandwidth is a constant value, it is difficult to reliably detect knocking from low speed rotation to high speed rotation.

発明の目的 本発明は上記従来の欠点を除去するものであ
り、エンジン回転数の広い範囲に亘つてノツキン
グに伴なう固有周波数信号を確実に検知すること
によつて、精度良くノツキング現象を検知するこ
とができるノツキング検知装置を提供するもので
ある。Purpose of the Invention The present invention eliminates the above-mentioned conventional drawbacks, and detects the knocking phenomenon with high accuracy by reliably detecting the natural frequency signal associated with knocking over a wide range of engine speeds. The object of the present invention is to provide a knocking detection device capable of detecting knocking.

発明の構成 本発明は上記目的を達成するために、エンジン
の回転数に応じてバンドパスフイルタの帯域幅を
可変することを特徴とするものである。Configuration of the Invention In order to achieve the above object, the present invention is characterized in that the bandwidth of the bandpass filter is varied in accordance with the rotational speed of the engine.

実施例の説明 以下に本発明の一実施例の構成について、図面
とともに説明する。DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

第３図において１１はエンジンの振動を検出す
る振動ピツクアツプであり、この振動ピツクアツ
プ１１としてはエンジンブロツクに固定する圧電
型センサ、エンジン音を検出するマイクロホン、
エンジン冷却水の中に配置され、冷却水の振動を
検出する水中マイクロフオン、又は水圧を検出す
る水圧センサが用いられる。１２は点火タイミン
グ入力、１３は増幅器、１４は帯域幅可変バンド
パスフイルタ、１５は回転数計、１６は制御部、
１７はROM（リードオンリーメモリー）、１８は
平均化回路、１９は増幅器、２０は比較器、２１
はノツキング判定出力端である。 In FIG. 3, numeral 11 is a vibration pickup for detecting engine vibrations, and this vibration pickup 11 includes a piezoelectric sensor fixed to the engine block, a microphone for detecting engine sound,
An underwater microphone placed in the engine coolant to detect vibrations of the coolant or a water pressure sensor to detect water pressure is used. 12 is an ignition timing input, 13 is an amplifier, 14 is a variable bandwidth bandpass filter, 15 is a rotation speed meter, 16 is a control unit,
17 is a ROM (read only memory), 18 is an averaging circuit, 19 is an amplifier, 20 is a comparator, 21
is the knocking judgment output terminal.

次に上記実施例の動作について説明する。第３
図において、振動ピツクアツプ１１の出力信号
は、増幅器１３で増幅され、帯域幅可変バンドパ
スフイルタ１４によりノツキングの固有周波数が
抽出される。また点火タイミング入力は回転数計
１５により、回転数に変換される。制御部１６
は、回転数１５の出力をもとに、ROM１７に書
き込まれている回転数に応じたバンドパスフイル
タの帯域幅に関する情報を読み出し、帯域幅可変
バンドパスフイルタ１４の帯域幅を決定する。比
較器２０は、平均化回路１８及び増幅器１９を通
つた信号と帯域幅可変バンドパスフイルタ１４の
信号レベルを比較して、ノツキング判定を行な
う。 Next, the operation of the above embodiment will be explained. Third
In the figure, the output signal of the vibration pickup 11 is amplified by an amplifier 13, and the natural frequency of knocking is extracted by a variable bandwidth bandpass filter 14. Further, the ignition timing input is converted into a rotational speed by a rotational speed meter 15. Control unit 16
Based on the output of the rotation speed 15, reads information written in the ROM 17 regarding the bandwidth of the bandpass filter according to the rotation speed, and determines the bandwidth of the variable bandwidth bandpass filter 14. The comparator 20 compares the signal level of the signal passing through the averaging circuit 18 and the amplifier 19 with the signal level of the variable bandwidth bandpass filter 14 to perform knocking determination.

次に上記帯域幅可変バンドパスフイルタ１４の
構成について第４図とともに説明する。 Next, the configuration of the variable bandwidth bandpass filter 14 will be explained with reference to FIG. 4.

第４図において、R11〜R1o、R3、R41〜R4o及
びR5、R6は抵抗、C1、C2はコンデンサ、MP×
１及びMP×２はマルチプレクサ、A1〜A3は演
算増幅器である。MP×１及びMP×２は、制御
部１６の信号からR11〜R1o及びR41〜R4oのうち
１つの抵抗を選定して導通とし、他の抵抗はオー
プンとする。 In Fig. 4, R 11 to R 1o , R 3 , R 41 to R 4o , R 5 and R 6 are resistors, C 1 and C 2 are capacitors, and MP×
1 and MP×2 are multiplexers, and A 1 to A 3 are operational amplifiers. For MP×1 and MP×2, one of the resistors R 11 to R 1o and R 41 to R 4o is selected and made conductive based on the signal from the control unit 16, and the other resistors are left open.

第４図において、R5＝R6とする中心周波数dl
０、帯域幅Wb、中心周波数における利得Ｈは、そ
れぞれ次の式となる。 In Figure 4, the center frequency dl with R 5 = R 6
0 , the bandwidth Wb, and the gain H at the center frequency are expressed by the following formulas.

dlp＝１／2πR3C1＝１／2πR2C2 ………(1) Wb＝１／R1kC1（ｋ＝１〜ｎ）………(2) Ｈ＝R1k／R4k（ｋ＝１〜ｎ） ………(3) ここでR11＝R41、R12＝R42、…、R1o＝R4oと
すれ(3)式より、常にＨ＝１となり利得Ｈは一定で
ある。 dl p = 1/2πR 3 C 1 = 1/2πR 2 C 2 ………(1) W b = 1/R 1k C 1 (k=1~n)……(2) H=R 1k /R 4k (k = 1 to n) ...... (3) Here, R 11 = R 41 , R 12 = R 42 , ..., R 1o = R 4o From equation (3), H = 1 and the gain H is constant.

また(1)、(2)式より、R1k（ｋ＝１〜ｎ）の抵抗
をマルチプレクサMP×１によつて選定すること
により、帯域幅Wbを中心周波数dlpと無関係に変
えることができる。 Also, from equations (1) and (2), by selecting the resistor R 1k (k = 1 to n) using the multiplexer MP x 1, the bandwidth W b can be changed independently of the center frequency dl p . can.

即ち、帯域幅可変バンドパスフイルタ１４は、
利得及び中心周波数と独立に帯域幅を決定できる
ものである。 That is, the variable bandwidth bandpass filter 14 is
The bandwidth can be determined independently of the gain and center frequency.

本実施例においてはノツキング信号を抽出する
帯域幅可変バンドパスフイルタ１４の帯域幅をエ
ンジン回転数に応じて可変でき、またこのとき中
心周波数及び利得はなんら変化しない構成となつ
ている。 In this embodiment, the bandwidth of the variable bandwidth bandpass filter 14 for extracting the knocking signal can be varied in accordance with the engine speed, and the center frequency and gain do not change at all.

ノツキングの固有周波数を抽出するフイルタの
選択性からすれば、できるだけ帯域幅を狭くする
ことが望ましいが、信号の時間的変動が大きくな
るに従つて、検知出力が減少することとなる。 Considering the selectivity of the filter that extracts the natural frequency of knocking, it is desirable to narrow the bandwidth as much as possible, but as the temporal fluctuation of the signal increases, the detection output decreases.

ノツキングによる振動の時間的変動が決まれば
それに適したフイルタの帯域幅が決定されること
となる。 Once the temporal fluctuation of vibration due to knocking is determined, the appropriate filter bandwidth can be determined.

発明の効果 本発明によれば、エンジン回転数に応じて変化
するノツキングの固有振動に対して、最適なフイ
ルタの帯域幅を設定できるため、低速回転から高
速回転までの巾広い範囲に亘つて、ノツキングの
検知精度を向上させることができる利点を有す
る。Effects of the Invention According to the present invention, the optimal filter bandwidth can be set for the natural vibration of knocking that changes depending on the engine speed, so that the filter can be used over a wide range from low speed rotation to high speed rotation. This has the advantage that the detection accuracy of knocking can be improved.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はノツキングを検知する振動ピツクアツ
プの周波数特性を示す図、第２図は従来のノツキ
ング検知装置のブロツク図、第３図は本発明の一
実施例におけるノツキング検知装置のブロツク
図、第４図は同装置の帯域幅可変フイルタの電気
回路図である。 １１……振動ピツクアツプ、１２……点火タイ
ミング入力、１３……増幅器、１４……帯域幅可
変バンドパスフイルタ、１５……回転数計、１６
……制御部、１７……ROM、１８……平均化回
路、１９……増幅器、２０……比較器、２１……
ノツキング判定出力端。 FIG. 1 is a diagram showing the frequency characteristics of a vibration pickup for detecting knocking, FIG. 2 is a block diagram of a conventional knocking detection device, FIG. 3 is a block diagram of a knocking detection device according to an embodiment of the present invention, and FIG. The figure is an electrical circuit diagram of the variable bandwidth filter of the same device. 11... Vibration pickup, 12... Ignition timing input, 13... Amplifier, 14... Bandwidth variable band pass filter, 15... Revolution meter, 16
...Control unit, 17...ROM, 18...Averaging circuit, 19...Amplifier, 20...Comparator, 21...
Knocking judgment output terminal.

Claims (1)

【特許請求の範囲】 １ エンジンの振動を検出する振動ピツクアツプ
と、前記振動ピツクアツプの出力信号を帯域通過
させる帯域幅可変バンドパスフイルタと、前記帯
域幅可変バンドパスフイルタの帯域幅をエンジン
の回転数に応じて可変する手段と、前記振動ピツ
クアツプの出力信号を平均化する平均化手段と、
前記帯域幅可変バンドパスフイルタの出力レベル
と前記平均化手段の出力レベルとを比較する比較
手段とを有することを特徴とするノツキング検知
装置。 ２ エンジン振動を検出する振動ピツクアツプと
して、エンジン音を検出するマイクロフオンを用
いた特許請求の範囲第１項記載のノツキング検知
装置。 ３ エンジン振動を検出する振動ピツクアツプと
して、エンジン冷却水の振動を検出する水中マイ
クロフオン、または水圧センサを用いた特許請求
の範囲第１項記載のノツキング検知装置。[Scope of Claims] 1: a vibration pickup for detecting engine vibration; a variable bandwidth bandpass filter for passing the output signal of the vibration pickup; and averaging means for averaging the output signal of the vibration pickup.
A knocking detection device comprising: comparison means for comparing the output level of the variable bandwidth bandpass filter and the output level of the averaging means. 2. The knocking detection device according to claim 1, wherein a microphone for detecting engine sound is used as a vibration pickup for detecting engine vibration. 3. The knocking detection device according to claim 1, which uses an underwater microphone or a water pressure sensor that detects engine cooling water vibrations as a vibration pickup that detects engine vibrations.
JP57177214A 1982-10-07 1982-10-07 Knocking detection device Granted JPS5965728A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57177214A JPS5965728A (en) 1982-10-07 1982-10-07 Knocking detection device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57177214A JPS5965728A (en) 1982-10-07 1982-10-07 Knocking detection device

Publications (2)

Publication Number Publication Date
JPS5965728A JPS5965728A (en) 1984-04-14
JPH0248045B2 true JPH0248045B2 (en) 1990-10-23

Family

ID=16027155

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57177214A Granted JPS5965728A (en) 1982-10-07 1982-10-07 Knocking detection device

Country Status (1)

Country Link
JP (1) JPS5965728A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2684611B2 (en) * 1989-04-14 1997-12-03 株式会社日立製作所 Knock detection device
FR3090047B1 (en) * 2018-12-14 2021-03-05 Continental Automotive France Method for detecting knocking combustion in an engine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55101318U (en) * 1979-01-09 1980-07-15

Also Published As

Publication number Publication date
JPS5965728A (en) 1984-04-14

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