Digital interferometric testing of ring surface

To solve the testing problem of ring surface, a non-splicing interference testing system is designed by combining digital phase measurement technology. Using closed-loop circuit feedback control to realize the precise control of PZT for small displacement, while collecting the N frame sequence interference light intensity map In (x,y). In order to reduce the adjustment error introduced by manual adjustment, the error correction matrix is derived based on the misalignment error model under the cylindrical coordinate system. It has been proved that the testing system can realize high precision detection of 360° rotary cylindrical surface, and a high precision Talyrond565LT cylindrical degree instrument is used to measure the same sample for comparison validation. The experimental results show that the ring surface detection system studied in this paper can realize one-time and high-precision detection of the inner surface of 360° cylinder, and the measurement accuracy PV is better than 0.4λ(0.25μm)and RMS is better than 0.2λ(0.12μm).