Combustion Induced Powertrain NVH - A Time-Frequency Analysis

Patro, T.N.

doi:10.4271/971874

Cited by 10 publications

(6 citation statements)

References 22 publications

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“…In figure 2 3). This is in accordance with a previous study, which found that combustion noise has a frequency band of 0.5-3.15 kHz [13]. Moreover, the fact that combustion noise has a frequency band of 1.3-3.5 kHz means that the combustion noise has a transient pattern, which cannot be expressed as a certain characteristic frequency, and that the pattern matching method by wavelet transform is more useful than FFT.…”

Section: Misfire Detection By Wavelet Transform Of Block Vibration Si...supporting

confidence: 92%

Detection of misfire and knock in spark ignition engines by wavelet transform of engine block vibration signals

Chang¹,

Kim²,

Min³

2002

Meas. Sci. Technol.

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The high-frequency components of engine block vibration signals during misfire and normal combustion show clear differences of duration and scale by wavelet analysis - continuous wavelet transform (CWT). A new factor, combustion noise intensity (`CNICWT'), has been defined, which has been derived from the CWT scalogram. It has been shown that CNICWT can detect misfire more accurately than fast Fourier transform power spectral density. Similarly, it has been found that CNICWT can also be applied to knock detection. The durations of both knock and misfire detection overlapped each other at the same wavelet scale 8; misfire, normal and knock cycles can be indicated on the same histogram by CNICWT. Moreover, knock and misfire detection can be combined to one CNICWT computation.

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Section: Misfire Detection By Wavelet Transform Of Block Vibration Si...supporting

confidence: 92%

Detection of misfire and knock in spark ignition engines by wavelet transform of engine block vibration signals

Chang¹,

Kim²,

Min³

2002

Meas. Sci. Technol.

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“…Effectiveness of engine block vibration signal analysis in detecting knocking in the SI engine or combustion start in the CI engine has already been proved through various research. Out of all signals acquired through the accelerometer, the vibration signal frequency band from 500 Hz to 4 kHz is most adequate in picking out vibration components generated by the incylinder pressure signal [19][20][21].…”

Section: Wavelet Transformation Of the Engine Block Vibration Signalmentioning

confidence: 99%

Detection of combustion start in the controlled auto ignition engine by wavelet transform of the engine block vibration signal

Kim¹,

Min²

2008

Meas. Sci. Technol.

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The CAI (controlled auto ignition) engine ignites fuel and air mixture by trapping high temperature burnt gas using a negative valve overlap. Due to auto ignition in CAI combustion, efficiency improvements and low level NO x emission can be obtained. Meanwhile, the CAI combustion regime is restricted and control parameters are limited. The start of combustion data in the compressed ignition engine are most critical for controlling the overall combustion. In this research, the engine block vibration signal is transformed by the Meyer wavelet to analyze CAI combustion more easily and accurately. Signal acquisition of the engine block vibration is a more suitable method for practical use than measurement of in-cylinder pressure. A new method for detecting combustion start in CAI engines through wavelet transformation of the engine block vibration signal was developed and results indicate that it is accurate enough to analyze the start of combustion. Experimental results show that wavelet transformation of engine block vibration can track the start of combustion in each cycle. From this newly developed method, the start of combustion data in CAI engines can be detected more easily and used as input data for controlling CAI combustion.

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“…Combustion noise is primarily transferred through the piston and connecting rod. This is dominant only below 1000 Hz [Patro, T.N., 1997]. A secondary combustion noise path which proves more useful for knock detection is through the cylinder block and cylinder head.…”

Section: Vibration-based Knock Detectionmentioning

confidence: 99%

Multivariate Knock Detection for Development and Production Applications

Tousignant

Reader

Tjong

2004

Transportation: Transportation and Environment

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Combustion knock caused by end gas autoignition continues to be a limiting factor in the performance of automotive internal combustion engines. As such, the availability of efficient knock detection methods is a prime requirement for the optimization of engine mapping and control. Current production knock control systems are based on the measurement of mechanical vibration induced by the acoustic resonance excited in the combustion chamber during autoignition. These vibrations are measured using accelerometers on the engine block. Conversely, knock detection in the laboratory environment during engine development or calibration generally involves either acoustic methods or acquisition of in-cylinder pressure. The purpose of this study is to develop an improved multi-transducer vibration-based knock detection method with applications in engine development and production. The possibility of replacing the pressure-based detection methods in the laboratory environment presents many advantages relating to cost and efficiency. Moreover, the economy of a vibration-based system coupled with improved correlation to laboratory methods represents great potential for performance improvements if applied to production applications.

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Combustion Induced Powertrain NVH - A Time-Frequency Analysis

Cited by 10 publications

References 22 publications

Detection of misfire and knock in spark ignition engines by wavelet transform of engine block vibration signals

Detection of misfire and knock in spark ignition engines by wavelet transform of engine block vibration signals

Detection of combustion start in the controlled auto ignition engine by wavelet transform of the engine block vibration signal

Multivariate Knock Detection for Development and Production Applications

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