Hybrid 3D Shape Measurement Using the MEMS Scanning Micromirror

Area of Science:

• Optical Metrology
• 3D Shape Measurement
• Surface Profilometry

Background:

• Measuring 3D shapes of surfaces with high reflectivity variations poses significant challenges for traditional optical methods.
• Existing techniques like fringe projection profilometry (FPP) and laser stripe scanning (LSS) have limitations in accuracy or robustness when dealing with such surfaces.

Purpose of the Study:

• To develop a hybrid 3D shape measurement system integrating FPP and LSS.
• To enhance the accuracy and robustness of 3D shape measurement for surfaces with large reflection variations.

Main Methods:

• Development of a biaxial Microelectromechanical Systems (MEMS) scanning micromirror projection system for pattern generation.
• Implementation of a quality-guided algorithm for a hybrid measurement scheme, using FPP for primary data and LSS for depth reconstruction.
• Application of a data fusion algorithm to merge data from both techniques for complete 3D reconstruction.

Main Results:

• The hybrid system demonstrated significant improvements in accuracy and robustness for surfaces with large reflection variations.
• Experimental results showed a 0.0278 mm improvement in accuracy and an 83.55% increase in measurement integrity.
• The proposed method effectively overcomes the limitations of individual FPP and LSS techniques.

Conclusions:

• The integrated FPP and LSS approach offers a superior solution for 3D shape measurement of complex surfaces.
• This hybrid system provides a more complete and accurate 3D reconstruction, especially for challenging industrial applications.
• The MEMS-based projection and quality-guided algorithm are key to the enhanced performance.