Extrinsic Calibration of a Laser Galvanometric Setup and a Range Camera

Area of Science:

• Metrology
• Optical Engineering
• Robotics

Background:

• Current galvanometric scanning systems use 2D planar calibration.
• This 2D method lacks accuracy for nonplanar or moving objects.
• Scanning laser Doppler vibrometers require precise laser aiming.

Purpose of the Study:

• To introduce a novel 3D calibration procedure for galvanometric scanning systems.
• To enhance laser beam aiming accuracy for diverse object geometries and movements.
• To improve the reliability of measurements in dynamic or complex environments.

Main Methods:

• Developed a 3D calibration procedure utilizing a 3D range sensor.
• Implemented a Non-Perspective-n-Point (NPnP) algorithm for calibration.
• Performed extrinsic calibration to determine object position relative to the scanning system.

Main Results:

• Achieved mean laser aiming accuracy below 10 mm for 95% of measurements.
• Demonstrated accuracy independent of object shape and movement between measurements.
• Outperformed the traditional 2D calibration method, which had errors below 68 mm.

Conclusions:

• The proposed 3D calibration method offers superior accuracy and robustness compared to 2D methods.
• This advancement is crucial for applications requiring precise laser targeting, such as in scanning laser Doppler vibrometry.
• The accuracy is primarily dependent on the performance of the 3D range sensor.