Searched for: subject%3A%22Laser%255C+Doppler%255C+vibrometer%22
(1 - 10 of 10)
document
Wansink, Nick (author)
Micromechanical resonators, which have become feasible due to advanced manufacturing techniques, have shown several interesting phenomena including mode coupling in a range of applications that span metrology and sensing. Conventional fabrication methods of these resonators have been used throughout the field. However, fabrication of...
master thesis 2024
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Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)
A transfer function (TF) is an effective representation of the load-response relationship of railway track structures. To fill the gap in measuring track structure TFs over a wide frequency range from a moving vehicle, we develop a TF measurement system and the associated TF estimation methodology. Accelerometers are utilized to estimate the...
journal article 2024
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Zeng, Y. (author)
doctoral thesis 2023
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Jin, J. (author)
Laser Doppler vibrometer (LDV) is a vibration-detecting instrument for noncontact and non-destructive measurement. It is superior to classic contact transducers in terms of the wide frequency range and high measurement resolution. LDV on moving platforms (LDVom) is one of the LDV measurement technology to one-way scan the vibrating surface, so...
doctoral thesis 2023
document
Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)
Due to train load and aging, the dynamic properties of railway tracks degrade over time and deviate over space, which should be monitored to facilitate track maintenance decisions. A train-borne laser Doppler vibrometer (LDV) can directly measure track vibrations in response to the moving train load, which can be potentially applied to large...
conference paper 2023
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Singh, Ajaypal (author)
Bicycle disc brake noise and vibration, which usually falls in the frequency range of 0-2 kHz, is a principal braking quality attribute that has started to attract significant interest from bicycle manufacturers. Brake noise is an irritant to their customers, who see it as a symptom of a defective brake and that leads to unnecessary warranty...
master thesis 2022
document
Zeng, Y. (author), Nunez, Alfredo (author), Li, Z. (author)
Speckle noise is a major problem for structural vibration measurements with Laser Doppler vibrometer on moving platform (LDVom) due to its highly random, frequent, and broadband nature, especially at high speeds. This paper develops a new post-processing framework to reduce speckle noise based on a case study of LDVom measurements on railway...
journal article 2022
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Jin, J. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)
Laser Doppler Vibrometer (LDV) is extensively applied in remote and precise vibration measurements for structural monitoring. Speckle noise is a severe signal issue restricting LDV applications, mainly when an LDV scans from moving platforms. Realistic simulations and thorough characterizations of speckle noise can support the despeckle...
journal article 2022
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Jin, J. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)
With increasing requirements for structural stability and durability, effective monitoring strategies for existing and potential damage are necessary. A laser Doppler vibrometer on moving platforms (LDVom) can remotely capture large-scale structural vibrations, but speckle noise, a significant signal issue mainly when one-way continuously...
journal article 2022
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Jin, J. (author), Li, Z. (author)
This paper presents a novel approach for eliminating speckle noises in Laser Doppler Vibrometer signals based on empirical wavelet transform (EWT). The moving root-mean-square thresholds are utilized to cut off signal drop-outs and produce noise discontinuity that EWT can identify. The extremum ratio behaves as the criterion to reject or accept...
conference paper 2021
Searched for: subject%3A%22Laser%255C+Doppler%255C+vibrometer%22
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