CAJ | 학술논문

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。
회전설비적순시전속시실현고장진단적중요삼수지일，야시제취표정설비운행상태기타관건삼수적기본전제。침대전통단시부리협변환방법존재순시전속고계정도불족적문제，제출일충기우자괄응단시Chirp-Fourier변환적순시전속고계방법。해방법건립조빈삼수적자괄응선취책략，가근거신호적시빈분포특성대신호진행자괄응필배분해，불단제고료계산효솔，이차피면료보도모호문제，실현순시전속적정학고계。재차기출상결합신호해조기술，형성무건상폭치상위해조방법，병성공응용우변공황하적치륜상고장진단。
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.