2134/5841
Ben Halkon
Ben
Halkon
Steve Rothberg
Steve
Rothberg
Synchronized-scanning laser vibrometry
Loughborough University
2010
Laser Doppler vibrometry
Scanning
Tracking
Synchronised-scanning
Vibration measurement
Rotating machinery
Operational deflection shapes
Mode shapes
Mechanical Engineering not elsewhere classified
2010-01-22 14:22:30
Conference contribution
https://repository.lboro.ac.uk/articles/conference_contribution/Synchronized-scanning_laser_vibrometry/9557663
The use ofLaser Vibrometers incorporating some form ofmanipulation ofthe laser beam orientation, typically using two
orthogonally aligned mirrors, has become increasingly popular in recent years with considerable attention being given to
the operation of such scanning Laser Vibrometers in continuous scanning mode. Here the laser beam orientation is a
continuous function oftime. making it possible, for example, to track a single point on a moving target such as a rotating
bladed disc. A recently derived comprehensive velocity sensitivity model has been developed to incorporate timedependent
beam orientation enabling confident and detailed analysis ofdata obtained in such measurements. The model
predicts the measured velocity for arbitrary mirror scan angles and arbitrary target motion and is shown to be especially
valuable in revealing the sources ofadditional components that occur in continuous scanning and tracking measurements
on rotors.
The development of the comprehensive velocity sensitivity model and of sophisticated measurement hardware and
software has resulted in proposal of the exciting new Synchronised-Scanning Laser Vibrometry technique. Introduced
for the first time in this paper, the measurement involves the probe laser beam tracking the rotating structure and
simultaneously scanning the region of interest to provide modal data under operating conditions, i.e. during rotation.
Such a measurement is inconceivable by any other means and the system that has been created has the potential to
provide data offundamental importance in the design and development ofa wide range ofdevices from hard disk drives
to gas turbines.