Analyzing real-time capability of raw laser-Doppler vibrometer signal combination for signal diversity

2021 ◽  
Author(s):  
Marvin Schewe ◽  
Christian Rembe
Keyword(s):  
Real Time ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Signal Combination ◽  
Signal Diversity

scholarly journals Signal Diversity for Laser-Doppler Vibrometers with Raw-Signal Combination

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 998
Author(s):  
Marvin Schewe ◽  
Christian Rembe
Keyword(s):  
Laser Doppler Vibrometer ◽  
Laser Speckle ◽  
Laser Doppler ◽  
Practical Implementation ◽  
Velocity Signal ◽  
Signal Combination ◽  
Signal Diversity ◽  
The Individual ◽  
Signal Dropout

The intensity of the reflected measuring beam is greatly reduced for laser-Doppler vibrometer (LDV) measurements on rough surfaces since a considerable part of the light is scattered and cannot reach the photodetector (laser speckle effect). The low intensity of the reflected laser beam leads to a so-called signal dropout, which manifests as noise peaks in the demodulated velocity signal. In such cases, no light reaches the detector at a specific time and, therefore, no signal can be detected. Consequently, the overall quality of the signal decreases significantly. In the literature, first attempts and a practical implementation to reduce this effect by signal diversity can be found. In this article, a practical implementation with four measuring heads of a Multipoint Vibrometer (MPV) and an evaluation and optimization of an algorithm from the literature is presented. The limitations of the algorithm, which combines velocity signals, are shown by evaluating our measurements. We present a modified algorithm, which generates a combined detector signal from the raw signals of the individual channels, reducing the mean noise level in our measurement by more than 10 dB. By comparing the results of our new algorithm with the algorithms of the state-of-the-art, we can show an improvement of the noise reduction with our approach.

Laser Doppler vibrometer for real-time speech-signal acquirement

2009 ◽  
Vol 7 (8) ◽  
pp. 732-733 ◽  
Author(s):  
尚建华 Jianhua Shang ◽  
贺岩 Yan He ◽  
刘丹 Dan Liu ◽  
臧华国 Huaguo Zang ◽  
陈卫标 Weibiao Chen
Keyword(s):  
Real Time ◽  
Speech Signal ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler

Temperature coefficient of Young’s modulus of silver microwhiskers determined by a laser Doppler vibration measurement

2021 ◽  
pp. 2150350
Author(s):  
Yijun Jiang ◽  
Mingyuan Lu ◽  
Shiliang Wang ◽  
Han Huang
Keyword(s):  
Temperature Dependence ◽  
Temperature Coefficient ◽  
Single Crystals ◽  
Young’S Modulus ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Young's Modulus ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Vibration Measurement

Temperature dependence of Young’s modulus of Ag microwhiskers was determined by a laser Doppler vibrometer. The Ag whiskers with diameters in sub-microns were synthesized by the use of physical vapor deposition (PVD). They have a five-fold twinned structure grown along the [1 1 0] direction. The temperature coefficient of Young’s modulus was measured to be [Formula: see text] ppm/K in the range of 300 K to 650 K. The measured values are very close to the reported values of [Formula: see text] ppm/K for bulk Ag single crystals. This finding can benefit the design of Ag-based micro/nano-electromechanical systems or micro/nano-interconnectors operated at elevated or lowered temperatures.

Identification of pavement material properties using a scanning laser Doppler vibrometer

2016 ◽  
Author(s):  
Navid Hasheminejad ◽  
Cedric Vuye ◽  
Wim Van den Bergh ◽  
Joris Dirckx ◽  
Jari Leysen ◽  
...  
Keyword(s):  
Material Properties ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Scanning Laser ◽  
Scanning Laser Doppler Vibrometer ◽  
Pavement Material
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