双频光栅用于动态过程破裂表面的三维重建

针对在冲击炮轰等快变化过程的傅里叶变换轮廓术测量中,CCD的拍摄速度低于物体的运动速度导致对动态条纹的时间采样不足,提出了采用双频正弦光栅进行测量的三维轮廓术,以傅里叶轮廓术为基础,利用低频光栅条纹图的截断相位做标记条纹,跟踪锁定高频光栅条纹图的同一级次条纹,利用高频光栅的变形条纹进行动态破裂物体的三维面形重建,有效的解决了在快变化动态过程的三维测量中因时间采样不足和条纹断裂带来的问题,正确的获得了物体的面形分布.计算机模拟实验和对瓷砖破裂过程的实际测量验证了此种方法的正确性.

3-D Surface Shape Restoration for Breaking Surface of Dynamic Process Based on Two-frequency Grating

In the quick change process of impact or blast,sampling rate of CCD is lower than object move rate,which result in deficiency of CCD's sampling.A novel method based on Fourier Transform Profilometry(FTP)was proposed,in which a two-frequency sine patterns is projected onto the object and the deformed fringe is captured by CCD.Some problems caused by deficiency of sampling and breaking fringes were solved in 3-D phase unwrapping by using the low-frequency grating unwrapping phase marked fringes.The same rank of high-frequency deformed fringes was tracked by marked fringes,and 3-D phase unwrapping by high-frequency grating fiinges was obtained.Computer simulation experiment and glazed tile rupture experiment proves the feasibility of this method.