中文摘要：

回转设备的瞬时转速是实现故障诊断的重要参数之一,也是提取表征设备运行状态其他关键参数的基本前提。针对传统短时傅里叶变换方法存在瞬时转速估计精度不足的问题,提出一种基于自适应短时Chirp-Fourier变换的瞬时转速估计方法。该方法建立调频参数的自适应选取策略,可根据信号的时频分布特性对信号进行自适应匹配分解,不但提高了计算效率,而且避免了谱图模糊问题,实现瞬时转速的精确估计。在此基础上结合信号解调技术,形成无键相幅值相位解调方法,并成功应用于变工况下的齿轮箱故障诊断。

英文摘要：

The instantaneous rotating speed carries a lot of useful information about the running condition of rotating machinery. It is also a key parameter for the condition monitoring and fault diagnosis. Traditional rotating speed estimation methods suffer from large estimation error due to low frequency resolution of short-time Fourier transform. To overcome this limitation, an instantaneous speed estimation method based on short-time Chirp-Fourier transform is proposed. In addition, an adaptive chirp rate selection scheme is further established. The analyzed signal could be decomposed in an adaptive way according to its time-frequency distribution in the proposed method. Hence the smearing problem could be avoided, and the computational efficiency is enhanced as well. On this basis, a tacho-less amplitude and phase demodulation technique is further proposed to detect the incipient fault of a gearbox during the non-stationary working conditions.