柴油机缸盖振动信号分形特征研究

针对柴油机振动信号的非线性特征，将小波变换与分形理论结合；由此进行缸盖振动信号的分析及故障特征的提取，进而对柴油机气阀间隙异常故障进行诊断。随后计算信号小波包频带盒维数、小波变换模极大及信号的多重分形谱。结果表明，这种将分形维数和多重分形谱的结构作为系统的衡量指标和故障的表征参数，使诊断结果简单、现实可行。

Study on the Fractal Feature of Cylinder-head Vibration Signal for Diesel Engines

Wavelet transform and fractal theory is combined with applied to analyze the cylinder head vibration signal of the diesel engine, and to extract fault feature according to the nonlinear characteristics of the vibration signal. This is to diagnosis diesel engine abnormal valve clearance fault, calculated wavelet packet frequency band box dimension, wavelet transform module maximum and the multifractal spectrum of the vibration signal. The results show that fractal dimension and multifractal spectrum as system measure and fault characteristic parameter, make the diagnosis results simple and feasible.