High-precision practical calibration method with virtual point constraint for line-structured light sensor

Area of Science:

• Engineering
• Metrology
• Optical Measurement Systems

Background:

• Wide fields of view and large depth of field in engineering measurements degrade line-structured light sensor accuracy.
• Existing calibration techniques are insufficient to mitigate these adverse effects.

Purpose of the Study:

• To develop a high-precision calibration method for line-structured light sensors.
• To overcome accuracy limitations caused by wide fields of view and large depth of field.

Main Methods:

• Calibration object design and virtual calibration point extraction.
• Development of a continuous linear displacement calibration platform.
• Detailed laser surface collection and description for enhanced calibration.

Main Results:

• Achieved Root Mean Square Error (RMSE) of 0.007 mm for gauge block measurements and 0.032 mm for rail profile measurements within a 260-540 mm range.
• Demonstrated significant accuracy improvements of 77.4% and 86.9% compared to the light plane method.
• Maintained high accuracy across the entire measurement range.

Conclusions:

• The proposed method offers a substantial advancement in high-precision calibration for line-structured light sensors.
• The technique maintains accuracy across the measurement range and enables automated calibration.
• This method holds significant practical value for diverse engineering applications.