Accurate 3D reconstruction of highly reflective mechanical part surfaces using a structured light method with combined phase shift and gray code

Abstract

The structured light measurement method is applied in quality control across various sectors including manufacturing, medicine, fashion, and technology. This approach facilitates the generation of rapid and consistent evaluation reports by analyzing errors, geometric dimensions, and deviations in measured parts, aligning them with design specifications. Such capabilities significantly enhance the speed and quality of production processes, particularly in the mechanical industry. This paper proposes an effective alternative solution for the inaccurate measurement of shiny mechanical surfaces. It explores ambient light to achieve optimal calibration and enhance measurement accuracy. The appropriate exposure time for surface measurement was determined by analyzing the image intensity histogram. This step helps avoid saturation in the detection device and ensures the generation of high-quality point clouds by merging them at suitable exposure times. To validate the effectiveness of the proposed system, two comparisons were conducted: one between the 3D profile of the part measured by commercial software versus the proposed method, and another between the 3D profile of the plastic part as measured by the proposed method versus its designed profile. The results demonstrate the efficiency of the proposed method in accurately testing full-field reflective surfaces, without requiring additional equipment or hardware.

Keywords

• Fringe projection
• 3D measurement
• High dynamic range
• Shiny surface