US 12,345,563 B2
Method and apparatus for interferometric vibration measurement at a plurality of measurement points by means of a measuring laser beam
Matthias Schüssler, Waldbronn (DE)
Assigned to Polytec GmbH, Waldbronn (DE)
Appl. No. 17/442,839
Filed by Polytec GmbH, Waldbronn (DE)
PCT Filed Mar. 9, 2020, PCT No. PCT/EP2020/056147
§ 371(c)(1), (2) Date Sep. 24, 2021,
PCT Pub. No. WO2020/193105, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 102019108124.6 (DE), filed on Mar. 28, 2019.
Prior Publication US 2022/0187120 A1, Jun. 16, 2022
Int. Cl. G01H 9/00 (2006.01)
CPC G01H 9/00 (2013.01) 15 Claims
OG exemplary drawing
 
1. A method for interferometric vibration measurement at a multiplicity of measurement points using a measurement laser beam (1),
the method comprising the steps of
A. generating the measurement laser beam (1) with a wavelength in an infrared wavelength range and a pilot laser beam (2) with a wavelength in a visible wavelength range;
B. after step A, deflecting the measurement laser beam (1) and the pilot laser beam (2) by a common optical deflection unit (8), and controlling the common optical deflection unit (8) so that the pilot laser beam (2) impinges on the measurement point; and
C. after step B, carrying out a vibration measurement using the measurement laser beam (1);
determining an angular deviation (11) between the pilot laser beam (2) and the measurement laser beam (1); and
in a correction step B1 between method steps B and C and after step B, actuating the common optical deflection unit (8) in order to compensate for the angular deviation (11) between the pilot laser beam (2) and the measurement laser beam (1) so that the measurement laser beam (1) impinges on the measurement point and the point of incidence of the pilot laser beam deviates, depending on the angular deviation, from the measurement point.