基于自适应线调频高斯基展开的参数识别方法

提出了用自适应线调频高斯基展开及其自适应谱进行参数识别的时频分析方法.用线调频高斯基函数自适应地对响应信号进行匹配分解,得到信号的线调频高斯基展开及其自适应谱.根据自适应谱从响应信号中重构出具有单频特性的振动信号,再由单自由度系统的参数识别方法识别系统的模态参数.并针对一多自由度系统具体论述了固有频率、阻尼比和振型的识别方法,识别结果与理论结果吻合较好.该方法不需要输入信号,并对平稳、非平稳信号均适用,且具有较强的抗噪声能力.算例分析说明提出的方法是参数识别的有效方法之一.

Modal parameter identification through adaptive chirplet-based signal approximation

A new method of modal parameter identification is proposed based on the time-frequency analysis of adaptive chirplet-based signal approximation and the adaptive spectrogram.The response signal can be adaptively decomposed by chirplet function,then,the chirplet-based signal approximation and adaptive spectrogram can be obtained.The signal,vibrating at a single natural frequency,can be reconstructed from the response signal according to the adaptive spectrogram,and modal parameters can be identified by the identification technique of single degree of freedom.The natural frequency,damping ratio and mode shape of a multi-degree-of-freedom system are analyzed and the identified results are in good agreement with the theoretical values.The method requires no input signal,regardless of whether the response is stationary or not,and is robust to noise.The simulations demonstrate that the proposed method is an effective method for modal parameter identification.