Omnidirectional dual-femtosecond absolute ranging for high-precision multi-target coordinate measurement

Area of Science:

• Metrology
• Optical Engineering
• Laser Technology

Background:

• Absolute ranging with femtosecond lasers offers wide measurement ranges, high precision, and speed.
• Large-scale, high-precision coordinate measurement presents challenges in geometric error compensation.

Purpose of the Study:

• To develop an omnidirectional femtosecond absolute ranging system for high-precision multi-target coordinate measurement in large-scale applications.
• To compensate for geometric errors and suppress rotary-axis-induced errors for enhanced accuracy.

Main Methods:

• Integration of a 2D universal-joint rotary axis with dual femtosecond laser absolute meters.
• Utilizing a standard sphere (40 nm sphericity) as a reflective reference and measurement origin.
• Employing a theoretical model to quantify geometric error influence and experimental validation.

Main Results:

• The femtosecond laser system achieves intrinsic distance precision within 5 µm.
• Multilateration-based coordinate measurement reaches sub-millimeter accuracy (<0.1 mm).
• Effective elimination of rotary-axis-induced geometric errors demonstrated.

Conclusions:

• The combination of a standard sphere and 2D universal joint provides a reliable solution for large-scale, high-precision multi-target coordinate measurement.
• This system is suitable for industrial metrology applications requiring precise spatial data.