Online 3D Displacement Measurement Using Speckle Interferometer with a Single Illumination-Detection Path

Area of Science:

• Optical Metrology
• Experimental Mechanics
• Materials Science

Background:

• Online, full-field, 3D displacement measurement is crucial for manufacturing.
• Existing methods often lack real-time capabilities or are complex.

Purpose of the Study:

• To propose an accurate and easy-to-implement method for online, nondestructive, full-field 3D displacement measurement.
• To utilize a single illumination-detection path for a compact optical system.

Main Methods:

• Employing an electronic speckle pattern interferometer (ESPI) with a single illumination-detection path.
• Utilizing spatial carrier phase-shifting technique for real-time data acquisition.
• Generating three distinct sensitivity vectors to measure orthogonal displacement components.

Main Results:

• Demonstrated the feasibility of the proposed ESPI system for 3D displacement measurement.
• Achieved real-time measurement of full-field displacements.
• Quantified the relative measurement error of the system.

Conclusions:

• The developed ESPI system offers an accurate and straightforward approach for online, nondestructive, 3D displacement analysis.
• The system's compact design and real-time capabilities make it highly suitable for industrial manufacturing.
• The study validates the effectiveness of combining ESPI with spatial carrier phase-shifting for comprehensive displacement evaluation.