Calibration method of line-structured light sensors based on a hinge-connected target with arbitrary pinch angles

Area of Science:

• Optics and Photonics
• Computer Vision
• Metrology

Background:

• Line-structured light 3D measurement is crucial for industrial 3D contour reconstruction.
• Accurate light plane calibration is essential for reliable 3D measurement systems.
• Traditional calibration methods can be time-consuming and require precise target placement.

Purpose of the Study:

• To develop an efficient and accurate calibration method for line-structured optical systems.
• To improve the speed and simplify the process of light plane calibration in industrial 3D measurement.
• To achieve high accuracy in 3D contour reconstruction using line-structured light.

Main Methods:

• A novel calibration method utilizing a hinge-connected double-checkerboards stereo target.
• Acquisition of a single image of the target under line-structured light.
• Solving 3D coordinates of feature points using external parameter matrix and camera system.
• Denoising point clouds and fitting the light plane using quadratic regression.

Main Results:

• The proposed method requires only one image for complete light plane calibration.
• Calibration is less sensitive to target angle and placement, improving speed and accuracy.
• Achieved a maximum Root Mean Square (RMS) error of 0.075 mm.
• Demonstrated simpler operation and higher effectiveness compared to traditional methods.

Conclusions:

• The developed calibration method significantly enhances the efficiency and accuracy of line-structured light 3D measurement systems.
• The technique is well-suited for complex industrial environments requiring rapid and precise 3D contour reconstruction.
• The hinge-connected double-checkerboards target offers a practical solution for calibrating optical systems.