【摘要】 提出了一种基于连续小波变换的时频域滤波方法,用于频响函数估计前的信号预处理。采用Morlet小波构造一种FIR滤波器对信号滤波,不会引起相位失真。提出了一种改进的小波基以满足瞬态激励情况的时频域分辨率要求。采用GARTEUR飞机模型构造仿真算例,对仿真数据添加白噪声。仿真结果表明,系统参数识别精度明显改善,滤波后获得的阻尼估计误差较滤波前下降了30%。更多还原

【Abstract】 A time-frequency de-noising method is presented in the frequency response function (FRF) preprocessing based on the continuous wavelet transform. Morlet wavelet is employed to construct a filter bank to reduce the noise. The filter bank is a finite impulse response (FIR) linear phase filter thus maintaining phase consistency. A modified Morlet base function is proposed to meet the time frequency resolution by using transient excitation. Numerical simulation is conducted using a Group for Aeronautical Research and Technology in Europe (GARTEUR) aircraft model excited by the transient input. The white noise is added to the simulated data. Results show that the accuracy of the system identification is improved. The estimated error of the mode damping is decreased by 30% compared with that obtained from the noise-corrupted signal.更多还原