Control unit of internal combustion engine

Patent metadata

Field	Value
Publication number	US-8949005-B2
Application number	US-201113246165-A
Country	US
Kind code	B2
Filing date	Sep 27, 2011
Priority date	May 17, 2011
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

A peak signal extracting device extracts a first peak value, being the maximum value of vibration level of a specified frequency in a predetermined crank angle range, and a crank angle; noise level storage device stores a noise vibration level; noise occurrence timing estimation device estimates a crank angle at which noise vibration peak takes place; and noise removing device calculates a second peak value based on the first peak value when a crank angle at which first peak value takes place and a crank angle at which noise peak value estimated to take place are not in coincidence, and calculates a second peak value based on the first peak value and noise peak value when the crank angles are identical. Even if the knocking vibration peak and noise vibration peak are overlapped, presence or absence of occurrence of knocking is determined precisely and a knocking strength is calculated properly.

First claim

What is claimed is:

1. A control unit of an internal combustion engine comprising:
a knocking sensor detecting a vibration waveform of an internal combustion engine;
a crank angle sensor detecting a crank angle of said internal combustion engine;
specified frequency extracting means extracting a vibration level of a specified frequency from a vibration waveform of said internal combustion engine;
peak signal extracting means extracting a first peak value, being the maximum value of the vibration level of said specified frequency in a predetermined crank angle range, and a crank angle at which said first peak value takes place;
noise level storage means in which stored is a vibration level of a noise to take place on said specified frequency due to operation of an electric or mechanical operating member that is provided in said internal combustion engine;
noise occurrence timing estimation means estimating a crank angle at which a noise peak value, being a peak value of said noise vibration, takes place, based on an operation timing of said operating member;
noise removing means calculating a second peak value based on said first peak value in the case that a crank angle at which said first peak value takes place and a crank angle at which said noise peak value is estimated to take place are not in coincidence, and calculating the second peak value based on said first peak value and said noise peak value in the case that a crank angle at which said first peak value takes place and a crank angle at which said noise peak value is estimated to take place are identical;
BGL calculation means calculating a background level (BGL), being the average of said second peak value;
threshold calculation means calculating a threshold for knocking determination based on said second peak value and said background level;
knocking determination means determining the presence or absence of the occurrence of a knocking based on said second peak value and said threshold for knocking determination;
knocking strength calculation means calculating a knocking strength based on said second peak value, said threshold for knocking determination and said background level when the occurrence of a knocking is determined by said knocking determination means;
retard amount calculation means calculating a knocking retard amount of an ignition timing based on a knocking strength having been calculated by said knocking strength calculation means; and
ignition timing correction means correcting an ignition timing based on the knocking retard amount having been calculated by said retard amount calculation means.

2. The control unit of an internal combustion engine according to claim 1 , wherein said noise removing means calculates a noise level correction coefficient for correcting said noise peak value based on a difference between a crank angle at which said first peak value takes place and a crank angle at which said noise peak value is estimated to take place, and calculates the second peak value based on said first peak value, said noise peak value and said noise level correction coefficient.

3. The control unit of an internal combustion engine according to claim 2 , wherein in the case that said operating member is a fuel injection valve, said noise level storage means corrects a vibration level of a noise having preliminarily been stored in accordance with a pressure value of a fuel to be injected and supplied to the internal combustion engine from said fuel injection valve.

4. The control unit of an internal combustion engine according to claim 3 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

5. The control unit of an internal combustion engine according to claim 2 , wherein in the case that said operating member is an intake valve or an exhaust valve, said noise level storage means corrects a vibration level of a noise having preliminarily been stored in accordance with a rotation speed or a load of the internal combustion engine.

6. The control unit of an internal combustion engine according to claim 5 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

7. The control unit of an internal combustion engine according to claim 2 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

8. The control unit of an internal combustion engine according to claim 1 , wherein in the case that said operating member is a fuel injection valve, said noise level storage means corrects a vibration level of a noise having preliminarily been stored in accordance with a pressure value of a fuel to be injected and supplied to the internal combustion engine from said fuel injection valve.

9. The control unit of an internal combustion engine according to claim 8 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

10. The control unit of an internal combustion engine according to claim 1 , wherein in the case that said operating member is an intake valve or an exhaust valve, said noise level storage means corrects a vibration level of a noise having preliminarily been stored in accordance with a rotation speed or a load of the internal combustion engine.

11. The control unit of an internal combustion engine according to claim 10 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

12. The control unit of an internal combustion engine according to claim 1 , wherein said noise level storage means stores a vibration level of a noise when there is no vibration level to take place resulted from combustion in a cylinder of the internal combustion engine.

Assignees

• Ono Takahiko
• Mitsubishi Electric Corp

Inventors

• Ono Takahiko

Classifications

• G01L23/225 Primary

  circuit arrangements therefor · CPC title

• F02P5/152

  dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22) · CPC title

• F02D35/027

  using knock sensors · CPC title

• F02D2041/288

  for performing a transformation into the frequency domain, e.g. Fourier transformation · CPC title

• G01L23/221

  for detecting or indicating knocks in internal combustion engines · CPC title