Chirp信号激励的电液伺服系统辨识

为得到某电液伺服转台系统的频率特性,采用Chirp信号作为激励。为解决原始时域采样信号直接经FFT处理得到的频率特性曲线严重畸变问题,对原始时域采样信号依次进行传统低通滤波、小波包去噪、高频段相位跳变修正后,再进行FFT,最后采用Smooth平滑滤波方法得到系统最终的频率特性曲线,满足了系统调试和性能评价的要求。

Identification of Electro hydraulic Servo System Based on Chirp Excitation Signal

In order to obtain frequency characteristic of an electro-hydraulic servo turntable system, Chirp signal was adopted as excitation.In order to solve the problem of serious distortion of frequency characteristic curves derived directly from Fast Fourier Trans-form ( FFT) of original time-domain sample signals, original time-domain sample signals were processed successively by low pass filte-ring, wavelet packet denoising, and amendment of phase hop at high frequency, and by FET.Finally, smooth filtering is used to ac-quire frequency characteristic curves, which really satisfy the requirement of system debugging and performance assessment.