瞬态位移干涉仪信号处理新方法

利用短时傅里叶变换计算速度快的特点,先对瞬态位移干涉仪信号进行预处理,得到速度的轮廓范围.据此估计小波变换中尺度因子的范围,然后用连续小波变换的方法对信号再次进行处理,用此方法分析计算机模拟出的位移干涉信号,恢复的速度相对误差小于2%.对高速爆轰实验中的位移干涉信号分别采用短时傅立叶变换、小波变换和二者相结合的方式进行分析,并记录三者的计算速度.实验表明,第三种方法能准确地恢复出物体的速度历史,计算误差在系统要求的范围内.本文综合计算速度和计算误差两方面的考虑,选择了适合于瞬态位移干涉信号处理的方法.

New Method for Signal Processing of Displacement Interferometer

For the fast calculation of the short time Fourier transform,the AFDISAR signal can be preprocessed by the proposed method to get a range of the speed of the slapper,and a range of the wavelet transform scale factor can be estimated.Then,the signal is analyzed by continuous wavelet transform method.The processing results of simulated interference signals suggest that the relative error is less than 2%.The displacement interferometer in high-speed detonation test is analyzed separately by method of short time Fourier transform,of wavelet transform and the method of short time Fourier transform combining with wavelet transform.The third method can recover the velocity history accurately,and calculate error is in the tolerated rang of the system.Taking calculating speed and calculating accuracy into consideration,the third method is chosen to the AFDISAR signal analysis.