Three-dimensional displacement measurement based on DIC-assisted polarization fringe projection

Abstract

Digital image correlation (DIC)-assisted fringe projection profilometry (FPP) is a recently developed method for measuring the shape and displacement of complex structures. However, FPP only requires the fringe pattern on the object surface while DIC only requires the texture pattern on the object surface. Therefore, separating high-quality fringe patterns and texture patterns has always been a research difficulty. In this paper, a texture-separable polarization phase-shift coding strategy (TSPP) is proposed to superimpose the phase-shift pattern of the horizontal polarization state and the white light texture pattern of the vertical polarization state into a new phase-shift fringe. Since the polarization states in two orthogonal directions do not affect each other, the texture pattern on the surface of the object can be obtained while projecting the phase-shifted fringes. Our proposed method can separate fringe patterns and texture patterns in real time without the need for additional hardware equipment, and can cope with different lighting environments to obtain high-quality fringe and texture patterns. Experimental results show that the proposed method can obtain better three-dimensional reconstruction effects and displacement measurement results.