Title:
DETECTING DEVICE FOR KNOCKING
Document Type and Number:
Japanese Patent JPH0526721
Kind Code:
A
Abstract:
PURPOSE:To enable decision of knocking irrespective of a state of operation by extracting three kinds of frequency components, at least, for each of a plurality of extracted frequency components and by varying a central frequency in accordance with the frequency out of them which has a maximum amplitude level. CONSTITUTION:Frequency components S1 and S3 according to each of a plurality of knocking vibration modes are extracted from an output signal of a knocking sensor. In three kinds of frequency analysis processings 111 to 113, on the occasion, frequency components of S11=f1-DELTAf, S12=f1 (central frequency matched with each component frequency f0) and S13=f1+DELTAf are extracted for each of the components S1 and S3. When the component S13 (S11) out of them shows a maximum, amplitude level, the frequency f1 is made high (low) by DELTAf. When the amplitude level of the component S12 is the maximum the frequency f1 is shifted by DELTAfX(x) ((x)=0 to 1) to the one of the components S11 and S13 which has the larger amplitude level. Since the central frequency follows automatically a change in each of the vibration modes, in this way, decision of knocking can always be performed irrespective of the state of operation of an engine.
Inventors:
KATOUGI KOUZOU
ICHIHARA TAKANOBU
TOKUDA HIROATSU
ICHIHARA TAKANOBU
TOKUDA HIROATSU
Application Number:
JP20376891A
Publication Date:
February 02, 1993
Filing Date:
July 19, 1991
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F02B77/08; F02D45/00; G01H17/00; G01L23/22; G01M15/00; (IPC1-7): F02B77/08; F02D45/00; G01H17/00; G01M15/00
Domestic Patent References:
| JPH0347449A | 1991-02-28 | |||
| JPH02154161A | 1990-06-13 | |||
| JPS60174918A | 1985-09-09 |
Attorney, Agent or Firm:
Kenjiro Take
Next Patent: JPH0526722