Abstract:Aiming at the problems of excessive sampling time interval and being subject to environmental disturbance existing in the pointdiffraction interferometric threedimensional measurement system based on a PZT phase shift, a pointdiffraction interferometric system used in transient threedimensional (3D) measurement is proposed. Through light beam polarization modulation and introducing polarization camera in the pointdiffraction interferometric system for 3D measurement, the transient phase shift interferometric measurement of 3D space coordinate is achieved. Aiming at the field of view (FOV) error existing in polarization camera and its influence on 3D measurement accuracy, the field of view (FOV) error calibration method based on phase interpolation is studied. In order to verify the feasibility of the system scheme, both numerical simulation and 3D online measurement comparison experiments were carried out, respectively. The experiment results show that with the proposed system, the transient threedimensional space measurement accuracy of the order of submicron can be achieved and the measurement repeatability is less than 5%. The proposed transient pointdiffraction interferometric system has the features of being not sensitive to environmental disturbance, high repeat measurement precision and rapid measurement, which provides a feasible method for the transient measurement of threedimensional displacement and dimension without guide rail.