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Simultaneous measurement of three linear displacements and two angular drifts using a single detector
Optics Express
|June 11, 2026
Summary
A new laser measurement method uses a single detector to precisely measure geometric errors in long precision systems. This approach simplifies complexity and significantly improves straightness accuracy over long distances.
Area of Science:
- Metrology and Precision Engineering
- Optical Measurement Systems
Background:
- Accurate geometric error evaluation of linear guideways is crucial for long-travel precision motion systems.
- Conventional multi-detector laser measurement schemes often suffer from system complexity.
Purpose of the Study:
- To propose a high-precision, efficient multi-degree-of-freedom (multi-DOF) measurement method.
- To reduce system complexity in measuring geometric errors of linear guideways.
Main Methods:
- Integration of heterodyne interferometry, laser autocollimation, and differential wavefront sensing.
- Utilizes a single-quadrant detector for simultaneous measurement of length, straightness errors, and angular drifts.
- Employs coherent demodulation for straightness signal decoupling and beam drift compensation.
Main Results:
- Successfully measured length, two-directional straightness errors, and two orthogonal angular drifts.
- Achieved significant reduction in straightness errors over a 2.5m range: horizontal from 7.82µm to 2.20µm, vertical from 11.57µm to 3.44µm.
- Validation experiments confirmed high effectiveness and reliability with excellent repeatability.
Conclusions:
- The proposed single-quadrant detector method offers a novel, compact, and efficient approach for laser-based multi-DOF error measurement.
- This method is particularly suitable for long-distance precision metrology applications.
- Demonstrated substantial improvement in measurement accuracy and system simplicity.
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