A new phase unwrapping method for phase shifting profilometry with object in motion

Phase unwrapping is an important step for the phase shifting profilometry. The dual-frequency phase unwrapping method can unwrap the object with discontinues when the object is static by employing more fringe patterns. However, errors will occur when moving object is reconstructed. In this paper, a new phase unwrapping method with dual-frequency phase unwrapping method for the moving object measurement is proposed. The fringe pattern with low fringe pattern and high frequency are projected onto the moving object surface. Then, the phase values are retrieved for the two frequencies respectively. The relationship between the movement and phase value is analyzed and the phase variations caused by the movement is compensated. At last, the phase value is unwrapped by the traditional dual-frequency phase unwrapping method. The effectiveness of the proposed method is verified by simulations.