Optical deflection measuring system

• Published in: Precision engineering Vol. 31; no. 3; pp. 188 - 195
• Main Authors: Vrhovec, Miha, Kovač, Igor, Munih, Marko
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.07.2007; Elsevier Science
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Laser deformation measurement; Magnetic and optical mass memories; Mechanical engineering. Machine design; Optical deflection measuring; Precision engineering, watch making; Real-time error compensation; Storage and reproduction of information; Optical deflection measuring; Real-time error compensation; Laser deformation measurement; Probabilistic approach; Precision engineering; Measurement sensor; Time measurement; Experimental study; Real time; Optical reading; Deformation measurement; Optical system; Error correction; Measurement accuracy; Read head; Optical fiber
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2006.06.004

A system for accurate real-time measurement of deflections was developed. A stable laser source is, by means of a single-mode fiber, coupled to an optical head located at one end of deformed structure. A detector circuit with a quadrant detector and processing electronics, located at the other end of the structure, communicates the resolved 2D position of the incident beam over a common digital bus. Experiments using interferometers were conducted in a climate-controlled chamber to evaluate system performance and verify the accuracy. A resolution of 0.1  μ m is attainable in dynamic measurements. The system was calibrated and tested to yield measurement accuracy of ± 0.8  μ m for ± 2 σ probability over the measurement range of ± 300  μ m. Drift of the system in the experimental setup was determined to be less than 2  μ m for measurement in both degrees of freedom within the 10 h period under constant environmental conditions.