【摘要】 针对内燃机缸盖振动信号的非平稳时变特点，通过给出小波包变换的一种改进算法，提出从振动信号的小波包分解系数中实现整循环征兆提取和故障识别的方法．实验结果表明了该方法的工程有效性．更多还原

【Abstract】 According to the non stationary and time varying characteristics of vibration signals measured on cylinder head, a unique technique for fault diagnosis of internal combustion engines by wavelet packets (WP) analysis is proposed. An improved algorithm for WP decomposition is put forward. This algorithm overcomes the existing frequency aliasing. By using such algorithm, an approach to signature extraction and fault identification is brought forth. The diagnostic signatures consist of the decomposed WP coefficients of the vibration signal synchronously sampled during a full working cycle. The experimental results show that this technique is simple to implement and may provide practical utility for vibration diagnosis in internal combustion engines as well as in other complex machines.更多还原