中文摘要：

针对变转速下的齿轮箱中复合故障的特征提取，提出了一种基于阶次分析与循环平稳解调的齿轮箱复合故障诊断方法。该方法先用线调频小波路径追踪算法从原始振动信号中提取转频信号，再根据转频信号对原始振动信号进行等角度重采样，将时域非平稳信号转化为角域周期平稳信号，最后对角域周期平稳信号进行循环平稳解调分析，根据故障特征阶次处的切片解调谱进行齿轮箱复合故障诊断。通过算法仿真和应用实例对包含齿轮局部故障和轴承局部故障的变转速齿轮箱复合故障进行了分析，分析结果表明，该方法在无转速计的情况下能有效地提取处于变转速下的齿轮箱复合故障的特征。

英文摘要：

Aiming at the problem of extracting fault characteristics from gearbox with compound faults under the conditions of changing rotating speed, a compound fault diagnosis method for gearbox based on order tracking and cyclostationary demodulation was proposed. In the proposed method, the rotating speed was estimated from original vibration signals by chirplet path pursuit algorithm. In or- der to transform the time domain non--stationary signals to the angular domain cyclostationary sig- nals,the even angle resampling was carried out to the original signals according to the obtained rota ting speed. The angular domain cyclostationary signals were analyzed by cyclostationary demodulation method, and the compound fault diagnosis of gearbox was executed according to the slice demodulation spectrum of fault characteristic order. The results obtained by analysis of the algorithm simulation and application examples to the gearbox with compound faults consisted of gear local fault and bearing lo- cal fault under the condition of changing rotating speed, show that the proposed method can extract fault characteristic effectively from gearbox with compound faults.