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Laser Doppler vibrometer

About: Laser Doppler vibrometer is a research topic. Over the lifetime, 6319 publications have been published within this topic receiving 76068 citations.


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Patent
09 Aug 2004
TL;DR: In this paper, a velocimeter is provided to detect the moving speed of a measuring object highly precisely, and a signal processing circuit part calculates the frequency shift quantity of the scattered light based on output from the photodiode.
Abstract: A first luminous flux emitted from the front end face of a LD is reflected by a mirror to be made incident on a detection point on the surface of a measuring object, and a second luminous flux emitted from the rear end face of the LD is reflected by another mirror to be made incident on the detection point. Scattered light from the first detection point is received in a photodiode. A signal processing circuit part calculates the frequency shift quantity of the scattered light based on output from the photodiode. As a result, a velocimeter is provided which detects the moving speed of a measuring object highly precisely.

26 citations

Journal ArticleDOI

26 citations

Journal ArticleDOI
TL;DR: In this paper, an acoustic-laser vibrometry method for nondestructive testing was studied by altering operational and defect parameters to determine their effects on measured signatures and system performance.
Abstract: Acoustic-laser vibrometry, a non-contact method for nondestructive testing, was studied by altering operational and defect parameters to determine their effects on measured signatures and system performance. The method detects delamination and voids in fiber-reinforced polymer reinforced concrete by vibrating the material with an acoustic excitation and measuring the vibration signature with a laser vibrometer. The operational parameters studied were excitation sound pressure level, laser signal, angle of incidence, and dwell time. The defect parameters studied were aspect ratio, size, and curvature. This study was undertaken to understand the method׳s phenomenology and to provide fundamental knowledge for an operational field system.

26 citations

Journal ArticleDOI
TL;DR: In this article, a laser Doppler velocimetry bench adapted for measuring acoustic particle velocities is used to measure sinusoidal structural velocity in order to assess the performance of two signal processing techniques, one available commercially and the other being developed in our laboratory.
Abstract: A laser Doppler velocimetry bench adapted for measuring acoustic particle velocities is used to measure sinusoidal structural velocities in order to assess the performance of two signal processing techniques, one available commercially and the other being developed in our laboratory. Considering a sinusoidal excitation signal of the vibrating structure, both techniques use frequency demodulation approaches in order to extract the instantaneous frequency of the Doppler signal which is scattered by the vibrating object and use synchronous analysis in order to estimate the amplitude and the phase of the velocities estimated by means of the frequency demodulation. The performance and limitations of the processing tools are evaluated by means of a comparison of the estimated velocities with reference values given by a laser vibrometer. Both systems show close and satisfactory performance up to 2?kHz for rms velocities higher than 1?mm?s?1.

26 citations

Patent
03 Aug 2012
TL;DR: In this paper, a Doppler lidar sensor system includes a laser generator that produces a highly pure single frequency laser beam, and a frequency modulator that modulates the laser beam with a highly linear frequency waveform.
Abstract: A Doppler lidar sensor system includes a laser generator that produces a highly pure single frequency laser beam, and a frequency modulator that modulates the laser beam with a highly linear frequency waveform. A first portion of the frequency modulated laser beam is amplified, and parts thereof are transmitted through at least three separate transmit/receive lenses. A second portion of the laser beam is used as a local oscillator beam for optical heterodyne detection. Radiation from the parts of the laser beam transmitted via the transmit/receive lenses is received by the respective transmit/receive lenses that transmitted the respective part of the laser beam. The received reflected radiation is compared with the local oscillator beam to calculate the frequency difference therebetween to determine various navigational data.

26 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202381
2022177
2021122
2020142
2019134
2018174