Measuring of drill bit vibration by laser Doppler methods

Abstract

The beginning of the drilling process was measured on the drill bit by laser Doppler interferometric methods. The measurements of the velocities were based on the Doppler effect. An LDV (Laser Doppler Vibrometer) device was used to measure the translational vibrations, and then the torsional vibrations (angular velocity changes) of the drill bit were investigated by an LTV (Laser Torsional Vibrometer) device. The time series and frequency spectra were also analysed.