Multi-dimensional information sensing of complex surfaces based on fringe projection profilometry

Abstract

Multi-dimensional and high-resolution information sensing of complex surface profiles is critical for investigating various structures and analyzing their mechanical properties. This information is currently accessed separately through different technologies and devices. Fringe projection profilometry (FPP) has been widely applied in shape measurement of complex surfaces. Since structured light information is projected instead of being attached onto the surface, it holds back accurately tracking corresponding points and fails to further analyze deformation and strain. To address this issue, we propose a multi-dimensional information sensing method based on digital image correction (DIC)-assisted FPP. Firstly, colorful fluorescent markers are introduced to produce modulated information with both high-intensity reflectivity and color difference. And then, the general information separation method is presented to simultaneously acquire speckle-free texture, fringe patterns and high-contrast speckle patterns for multi-dimensional information sensing. To the best of our knowledge, this proposed method, for the first time, simultaneously realizes accurate and high-resolution 2D texture (T), 4D shape (x, y, z, t) and analytical dimensional mechanical parameters (deformation (d), strain (s)) information sensing based on the FPP system. Experimental results demonstrate the proposed method can measure and analyze 3D geometry and mechanical state of complex surfaces, expanding the measuring dimension of the off-the-shelf FPP system without any extra hardware cost.