Optimization for calibration of large-scale optical measurement positioning system by using spherical constraint

Area of Science:

• Metrology
• Optical Measurement Systems
• Calibration Techniques

Background:

• Measurement accuracy in large-scale optical positioning systems is heavily reliant on calibration procedures.
• Existing methods may have limitations in providing comprehensive directional constraints.

Purpose of the Study:

• To present a more reliable calibration approach for optical measurement positioning systems using spherical constraints.
• To improve the estimation accuracy of orientation parameters and overall system precision.

Main Methods:

• Development of an adjustment model based on spherical constraints.
• Implementation of an optimization calculation method for the calibration procedure.
• Utilizing spherical constraints to provide directional control in the system's workspace.

Main Results:

• The proposed method offers constraints in all directions within the workspace.
• Orientation parameters are estimated more accurately compared to current techniques.
• Experimental data demonstrate an improved accuracy in the depth direction.
• The average 3D coordinate error, validated against a laser tracker, is approximately 0.18 mm across the entire workspace.

Conclusions:

• The spherical constraint calibration method significantly enhances the accuracy of large-scale optical measurement positioning systems.
• This approach offers a more robust and precise calibration solution, particularly improving depth accuracy.