A Dual Beam Laser Vibrometer for Measurement of Dynamic Structural Rotations and Displacements

✍ Scribed by M.W. Trethewey; H.J. Sommer; J.A. Cafeo

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 586 KB
• Volume: 164
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1993.1197

✦ Synopsis

A novel non-contacting system for multiaxis vibration measurements (one translation and two angular deflections) is described. The system is based on monitoring the reflections of two laser beams from a planar reflective target. By utilizing the geometry of the beams and their respective reflections: range, pitch and roll of the target can be determined. The theory behind the system is discussed along with the development of a prototype device. Static and dynamic experiments are performed to determine the system's operational limits and utility. The prototype system demonstrated the capability of measuring motions up to (1 \mathrm{kHz}) with absolute accuracies of (0.04 \mathrm{~mm}) for the translation variable and 0.03 degrees for the rotation variables. Measurement precision of (0.01 \mathrm{~mm}) and 0.01 degrees approached the precision of the test stand and the theoretical resolution limits of the system over a usable workspace of (\pm 2.5 \mathrm{~mm}) and (\pm 5) degrees.