METHOD FOR DETECTING COMBUSTION NOISE IN INTERNAL COMBUSTION ENGINE, COMBUSTION NOISE DETECTION DEVICE, AND DEVICE FOR CONTROLLING INTERNAL COMBUSTION ENGINE

• US 20140172280A1
• Filed: 07/26/2012
• Published: 06/19/2014
• Est. Priority Date: 07/28/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Okamoto, Takashi, Ogata, Kenichiroh, Watanabe, Daisuke
• Granted Patent: US 9,494,098 B2
• Time in Patent Office: Days
• US Class Current: 701/111
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: F02D 13/0242 Variable control of the exhaust valves only
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 2041/1432 the system including a filter, e.g. a low pass or high pass filter
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/025 Engine noise, e.g. determined by using an acoustic sensor
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/1493 Details
• CPC Class Codes: F02D 41/3017 characterised by the mode(s) being used
• CPC Class Codes: F02D 41/40 with means for controlling injection timing or duration
• CPC Class Codes: F02P 5/04 automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions dependent on position of personal controls of engine F02P5/02
• CPC Class Codes: G01H 17/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups see provisionally also G01H1/00
• CPC Class Codes: G01M 15/12 by monitoring vibrations
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Although a method for changing a combustion method taking place in an internal combustion engine depending on running condition is proposed, it can be considered that conditions under which a combustion noise occurs naturally differ with different methods. A detection method of prior art is not compatible with different combustion methods and the accuracy of combustion noise detection was low. Accurate combustion noise detection is enabled by identifying a combustion mode taking place in the internal combustion engine, selecting a sensed frequency or frequency band of a combustion noise sensor that detects a combustion noise in a combustion chamber of the internal combustion engine according to the combustion mode, and detecting a combustion noise.

Claims

1. A method for detecting a combustion noise in an internal combustion engine for use in a control device that computes a comparative magnitude of a combustion noise by frequency analysis processing on a frequency signal from a combustion noise sensor that detects a combustion noise in a combustion chamber of the internal combustion engine as a frequency output, the method characterized in that the control device

(1) identifies a combustion mode taking place in the combustion chamber, which is set depending on running condition, and selects a proper sensed frequency of the combustion noise sensor for the combustion mode;

and

(2) computes a comparative magnitude of a combustion noise specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output.

2. The method for detecting a combustion noise in an internal combustion engine according to claim 1, characterized in that the combustion mode is set to one of combustion modes comprising at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition, and a sensed frequency of the combustion noise sensor for the compression ignited combustion is set to a lower value than a sensed frequency of the combustion noise sensor for the spark ignited combustion.

7. The method for detecting a combustion noise in an internal combustion engine according to claim 1, characterized in that the combustion mode taking place in the combustion chamber, which is set depending on running condition, is one of the following modes:

compression ignited combustion, lean combustion, exhaust gas recirculation combustion, and stoichiometric spark ignited combustion, and a sensed frequency among these modes is lowest in compression ignited combustion, higher in lean combustion, even higher in exhaust gas recirculation combustion, and highest in stoichiometric spark ignited combustion.

3. A method for detecting a combustion noise in an internal combustion engine for use in a control device that computes a comparative magnitude of vibration by frequency analysis processing on a frequency signal from a non-resonant knock sensor that detects vibration caused by combustion in a combustion chamber of the internal combustion engine as a frequency output, the method characterized in that the control device

(1) identifies a combustion mode taking place in the combustion chamber, which is set depending on running condition, and selects a proper sensed frequency of the knock sensor for the combustion mode;

and

(2) computes a comparative magnitude of vibration specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output.

4. The method for detecting a combustion noise in an internal combustion engine according to claim 3, characterized in that the combustion mode is set to one of combustion modes comprising at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition, and a sensed frequency of the knock sensor for the compression ignited combustion is set to a lower value than a sensed frequency of the knock sensor for the spark ignited combustion.

5. The method for detecting a combustion noise in an internal combustion engine according to claim 4, characterized in that a sensed frequency band of the knock sensor for the spark ignited combustion is set to a band including sensed frequencies having at least two or more distinct peaks and a sensed frequency band of the knock sensor for the compression ignited combustion is set to a band including a sensed frequency having a single distinct peak.

6. The method for detecting a combustion noise in an internal combustion engine according to claim 4, characterized in that sensed frequency bands of the knock sensor for the spark ignited combustion are set to two or more bands respectively including center frequencies having at least two or more distinct peaks and a sensed frequency band of the knock sensor for the compression ignited combustion is set to a band including a center frequency having a single distinct peak.

8. A device for detecting a combustion noise in an internal combustion engine, the device computing a comparative magnitude of a combustion noise by frequency analysis processing on a frequency signal from a combustion noise sensor that detects a combustion noise in a combustion chamber of the internal combustion engine as a frequency output, the device characterized by comprising:

a combustion mode identifying means that identifies a combustion mode taking place in the combustion chamber, which is set depending on running condition;

a frequency selecting means that selects a sensed frequency of the combustion noise sensor, which has been predetermined to be specific to a combustion mode identified; and

a combustion noise computing unit that computes a comparative magnitude of a combustion noise specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output.

9. The device for detecting a combustion noise in an internal combustion engine according to claim 8, characterized in that the combustion mode identifying means identifies at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition, and the frequency selecting means selects a sensed frequency predetermined for the spark ignited combustion if the spark ignited combustion is identified and selects a sensed frequency predetermined for the compression ignited combustion, which is lower than the sensed frequency for the spark ignited combustion, if the compression ignited combustion is identified.

14. The device for detecting a combustion noise in an internal combustion engine according to claim 8, characterized in that the combustion mode taking place in the combustion chamber, which is set depending on running condition, is one of the following modes:

compression ignited combustion, lean combustion, exhaust gas recirculation combustion, and stoichiometric spark ignited combustion, and a sensed frequency among these modes is lowest in compression ignited combustion, higher in lean combustion, even higher in exhaust gas recirculation combustion, and highest in stoichiometric spark ignited combustion.

10. A device for detecting a combustion noise in an internal combustion engine, the device computing a comparative magnitude of vibration by frequency analysis processing on a frequency signal from a non-resonant knock sensor that detects vibration caused by combustion in a combustion chamber of the internal combustion engine as a frequency output, the device characterized by comprising:

a combustion mode identifying means that identifies a combustion mode taking place in the combustion chamber, which is set depending on running condition;

a frequency selecting means that selects a sensed frequency of the knock sensor, which has been predetermined to be specific to a combustion mode identified; and

a combustion noise computing unit that computes a comparative magnitude of vibration specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output.

11. The device for detecting a combustion noise in an internal combustion engine according to claim 10, characterized in that the combustion mode identifying means identifies at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition, and the frequency selecting means selects a sensed frequency predetermined for the spark ignited combustion if the spark ignited combustion is identified and selects a sensed frequency predetermined for the compression ignited combustion, which is lower than the sensed frequency for the spark ignited combustion, if the compression ignited combustion is identified.

12. The device for detecting a combustion noise in an internal combustion engine according to claim 10, characterized in that the frequency selecting means selects a frequency band including sensed frequencies having at least two or more distinct peaks if the spark ignited combustion is identified and selects a frequency band including a sensed frequency having a single distinct peak if the compression ignited combustion is identified.

13. The device for detecting a combustion noise in an internal combustion engine according to claim 10, characterized in that the frequency selecting means selects two or more frequency bands respectively including center frequencies having at least two or more distinct peaks if the spark ignited combustion is identified and selects a frequency band including a center frequency having a single distinct peak if the compression ignited combustion is identified.

15. A device for detecting a combustion noise in an internal combustion engine, the device computing a comparative magnitude of vibration by frequency analysis processing on a frequency signal from a knock sensor that detects vibration caused by combustion in a combustion chamber of the internal combustion engine as a frequency output, the device characterized by comprising:

a combustion mode identifying means that identifies a combustion mode taking place in the combustion chamber, which is set depending on running condition;

a frequency selecting means that selects either a frequency signal from a resonant knock sensor or a frequency signal from a non-resonant knock sensor according to a combustion mode identified; and

a combustion noise computing unit that computes a comparative magnitude of vibration specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output.

16. The device for detecting a combustion noise in an internal combustion engine according to claim 15, characterized in that the combustion mode identifying means identifies at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition, and the frequency selecting means selects a frequency signal from the non-resonant knock sensor if the spark ignited combustion is identified and selects a frequency signal from the resonant knock sensor if the compression ignited combustion is identified.

17. A device for controlling an internal combustion engine, wherein the device comprises a combustion noise detecting unit that computes a comparative magnitude of a combustion noise by frequency analysis processing on a frequency signal from a combustion noise sensor that detects a combustion noise in a combustion chamber of the internal combustion engine that is run in a combustion mode which is set depending on running condition as a frequency output and drives a regulatory mechanism that controls combustion in the internal combustion engine according to an output of the combustion noise detecting unit, the device characterized by comprising:

a combustion mode identifying means that identifies a combustion mode which is set depending on the running condition;

a frequency selecting means that selects a sensed frequency of the combustion noise sensor, which has been predetermined to be specific to a combustion mode identified;

a combustion noise computing unit that computes a comparative magnitude of a combustion noise specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output; and

a regulating means that, if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, controls combustion so that an actual combustion noise becomes less than the predetermined value of combustion noise by action of the regulatory mechanism.

18. (canceled)

19. (canceled)

20. A device for controlling an internal combustion engine, wherein the device comprises a combustion noise detecting unit that computes a comparative magnitude of vibration by frequency analysis processing on a frequency signal from a knock sensor that detects vibration caused by combustion in a combustion chamber of the internal combustion engine that is run in a combustion mode which is set depending on running condition as a frequency output and drives a regulatory mechanism that controls combustion in the internal combustion engine according to an output of the combustion noise detecting unit, the device characterized by comprising:

a combustion mode identifying means that identifies the combustion mode, which is either of at least spark ignited combustion in which air-fuel mixture is ignited by an ignition plug and compression ignited combustion in which air-fuel mixture or air is compressed by a piston, thus causing self-ignition;

a frequency selecting means that selects a sensed frequency predetermined for the spark ignited combustion if the spark ignited combustion is identified and selects a sensed frequency predetermined for the compression ignited combustion, which is lower than the sensed frequency for the spark ignited combustion, if the compression ignited combustion is identified;

a combustion noise computing unit that computes a comparative magnitude of a combustion noise specific to the combustion mode taking place in the combustion chamber by frequency analysis processing on the selected sensed frequency output; and

an ignition correction means that, when it is determined that the mode is the spark ignited combustion by the combustion mode identifying means, and if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, delays ignition timing so that an actual combustion noise becomes less than the predetermined value of combustion noise by action of an ignition device which is one component of the regulatory mechanism; and

a means for correction by the regulatory mechanism, wherein the means, when it is determined that the mode is the compression ignited combustion by the combustion mode identifying means, and if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, controls combustion so that an actual combustion noise becomes less than the predetermined value of combustion noise by using one of at least the following;

valve regulating devices that control the open/close timing and open/close lift of an intake valve and an exhaust valve of the internal combustion engine;

an injector valve that controls the injection timing and period of fuel which is fed into the internal combustion engine;

a supercharger that controls supercharging pressure of air which is fed into the internal combustion engine; and

a vehicle driving motor that increases or decreases the drive torque or generator torque in a hybrid car action of another component of the regulatory mechanism than the ignition device, which are other components of the regulatory mechanism than the ignition device.

21. The device for controlling an internal combustion engine according to claim 20, characterized in that the means for correction by the regulatory mechanism performs at least one of the following controls:

(1) if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, delaying the exhaust valve close timing by the valve regulating devices and maintaining the close timing when the output of the combustion noise computing unit has become less than the predetermined value of combustion noise;

(2) if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, shortening the injector valve open period and maintaining the open period when the output of the combustion noise computing unit has become less than the predetermined value of combustion noise;

(3) if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, increasing supercharging pressure of the supercharger and maintaining the supercharging pressure when the output of the combustion noise computing unit has become less than the predetermined value of combustion noise; and

(4) if an output of the combustion noise computing unit is more than a predetermined value of combustion noise, increasing the drive torque of the vehicle driving motor and decreasing the generator torque and maintaining the drive torque and the generator torque when the output of the combustion noise computing unit has become less than the predetermined value of combustion noise.