空间位相检测数字滤波器的设计

Design of Digital Filter Used in Spatial Phase Detection

在空间载波条纹位相检测中，滤波函数的选择对解调相位的精度和速度起着决定性的作用。文中系统地分析了滤波方式和滤波器的性能对空间位相检测的影响，把空间载波条纹分成窄带调相载波条纹和宽带调相载波条纹两类，分别给出了特征多项式设计法和窗函数设计法。窄带调相条纹解调滤波器的幅频特性要求在解调载波及高次谐波处幅值为零，在这些频率附近滤波器的幅值应尽量地小。宽带条纹的滤波器则要求通带平坦，阻带纹波小，同时满足在解调载波频率处幅值尽量小的条件。为了验证设计原则和方法的正确性，文中还给出了根据这些原则和方法设计的滤波器解调计算机模拟信号的结果。

The property of digital filters for spatial phase detection significantly influences the accuracy and the speed of phase demodulation. This paper systematically reviews phase demodulation methods in spatial carrier fringe pattern analysis. The spatial carrier fringes are divided into narrow and wide band phase modulated fringes. The design of the digital filters is separately proposed for both the narrow and the wide band phase modulated carrier fringes. The demodulated results of simulated signals of computer are presented according to the principles and the methods designed for digital filters.