A Three-Dimensional Structured Light Vision System by Using a Combination of Single-Line and Three-Line Lasers

Area of Science:

• Optical Metrology
• 3D Scanning Technology
• Computer Vision

Background:

• Traditional 3D scanning methods often require complex mechanical setups like precision sliding rails and displacement measurement equipment.
• Accurate real-time calibration of the light plane is crucial for reliable 3D shape recovery.
• Obtaining complete 3D data for objects, especially from challenging angles, remains a significant hurdle in optical metrology.

Purpose of the Study:

• To propose a novel multi-line structured light measurement method that simplifies the 3D scanning process.
• To develop a system that eliminates the need for precision sliding rails and displacement measurement equipment.
• To achieve real-time calibration of the scanned light plane for accurate 3D shape reconstruction.

Main Methods:

• A hybrid approach combining single-line and three-line structured light projection.
• The single-line laser is moved to intersect with a fixed three-line laser, creating three intersection points.
• Camera coordinates of these intersection points are used to solve for the single-line light plane, enabling real-time calibration.

Main Results:

• The proposed method successfully performs real-time calibration of the scanned light plane.
• It enables the scanning of the single-line laser at any angle, facilitating the determination of the object's complete 3D shape.
• Experimental results demonstrate a repetition error of under 0.16 mm, suitable for complex workpiece measurement.

Conclusions:

• The developed multi-line structured light method effectively overcomes limitations in capturing data from difficult angles and locations.
• It provides a robust and precise solution for recovering the 3D shapes of complicated workpieces.
• The system offers a simplified and accurate alternative to existing 3D measurement techniques.