DIGITAL MOIRE SYSTEM WITH PHASE SHIFTING METHOD

A new deformation measurement technique with digital moire methods is presented. The image of a grating bonded onto a body under exa min ation is acquired with a CCD camera. The sample frequency is chosen as the times of grating density. Then, a special phase shifting method is realized by using digital signal processing technique. The influence of phase shift error and high harmonics in grating signal is automatically corrected.