An accelerometer with integrative intensity-modulated optical encoder and patterned leaf spring for low-frequency vibration monitoring

2016 ◽  
Vol 251 ◽  
pp. 75-83 ◽  
Author(s):  
Hongzhong Liu ◽  
Haoyu Yu ◽  
Weitao Jiang ◽  
Xuan Li ◽  
Shanjin Fan ◽  
...  
Keyword(s):  
Low Frequency ◽  
Vibration Monitoring ◽  
Leaf Spring ◽  
Optical Encoder ◽  
Intensity Modulated ◽  
Low Frequency Vibration

Highly Sensitive Supermode Interferometer for Low Frequency Vibration Monitoring

2021 ◽  
Author(s):  
Josu Amorebieta ◽  
Angel Ortega-Gomez ◽  
Gaizka Durana ◽  
Enrique Antonio-Lopez ◽  
Axel Schülzgen ◽  
...  
Keyword(s):  
Low Frequency ◽  
Vibration Monitoring ◽  
Low Frequency Vibration ◽  
Highly Sensitive

scholarly journals Development of a High-Sensitivity Optical Accelerometer for Low-Frequency Vibration Measurement

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2910 ◽  
Author(s):  
Rui-Jun Li ◽  
Ying-Jun Lei ◽  
Zhen-Xin Chang ◽  
Lian-Sheng Zhang ◽  
Kuang-Chao Fan
Keyword(s):  
Passive Control ◽  
Low Cost ◽  
Low Frequency ◽  
High Sensitivity ◽  
Dynamic Responses ◽  
Vibration Measurement ◽  
Leaf Spring ◽  
Seismic Mass ◽  
Low Frequency Vibration ◽  
Low Amplitude

Low-frequency vibration is a harmful factor that affects the accuracy of micro/nano-measuring machines. Low-frequency vibration cannot be completely eliminated by passive control methods, such as the use of air-floating platforms. Therefore, low-frequency vibrations must be measured before being actively suppressed. In this study, the design of a low-cost high-sensitivity optical accelerometer is proposed. This optical accelerometer mainly comprises three components: a seismic mass, a leaf spring, and a sensing component based on a four-quadrant photodetector (QPD). When a vibration is detected, the seismic mass moves up and down due to the effect of inertia, and the leaf spring exhibits a corresponding elastic deformation, which is amplified by using an optical lever and measured by the QPD. Then, the acceleration can be calculated. The resonant frequencies and elastic coefficients of various seismic structures are simulated to attain the optimal detection of low-frequency, low-amplitude vibration. The accelerometer is calibrated using a homemade vibration calibration system, and the calibration experimental results demonstrate that the sensitivity of the optical accelerometer is 1.74 V (m·s−2)−1, the measurement range of the accelerometer is 0.003–7.29 m·s−2, and the operating frequencies range of 0.4–12 Hz. The standard deviation from ten measurements is under 7.9 × 10−4 m·s−2. The efficacy of the optical accelerometer in measuring low-frequency, low-amplitude dynamic responses is verified.

Study on the Characteristics of Low-Frequency Vibration of the Core of Single Phase Transformer Set Caused by GIC

2014 ◽  
Vol 716-717 ◽  
pp. 1162-1167
Author(s):  
Xiao Ran Pei ◽  
Lian Guang Liu
Keyword(s):  
Single Phase ◽  
Low Frequency ◽  
Linear Increase ◽  
Phase Changes ◽  
Vibration Monitoring ◽  
Location Selection ◽  
The Core ◽  
Low Frequency Vibration ◽  
Dc Bias ◽  
Selection Of

The study on characteristics of transformer vibration caused by GIC is the foundation of studies on transformer noise caused by GIC, location selection of monitoring vibration and noise. In this study, the characteristics of low-frequency vibration of the core of single phase transformer sets caused by GIC have been analyzed through building mathematical models and experimental analysis. The results show that when DC bias occurs the vibration signals contain 50 Hz and 150 Hz vibration. With the degree of DC bias the 50 Hz vibration grows by linear increase and 150 Hz vibration grows by square increase. Affected by GIC, the 50 Hz and 150 Hz vibration waveform’s phase changes with alternate 0 andπ. The characteristics of 50 Hz and 150 Hz vibration discriminate between core vibration caused by GIC and HVDC grounding currents. This study has significance for vibration monitoring of transformer faults, and can assist in determining the level of GIC.

scholarly journals Low Frequency Vibration Visual Monitoring System Based on Multi-Modal 3DCNN-ConvLSTM

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5872
Author(s):  
Alimina Alimasi ◽  
Hongchen Liu ◽  
Chengang Lyu
Keyword(s):  
Monitoring System ◽  
Visual Information ◽  
Spatial Information ◽  
Low Frequency ◽  
Environmental Safety ◽  
Microsoft Kinect ◽  
Vibration Monitoring ◽  
Kinect V2 ◽  
Low Frequency Vibration ◽  
Spatiotemporal Feature

Low frequency vibration monitoring has significant implications on environmental safety and engineering practices. Vibration expressed by visual information should contain sufficient spatial information. RGB-D camera could record diverse spatial information of vibration in frame images. Deep learning can adaptively transform frame images into deep abstract features through nonlinear mapping, which is an effective method to improve the intelligence of vibration monitoring. In this paper, a multi-modal low frequency visual vibration monitoring system based on Kinect v2 and 3DCNN-ConvLSTM is proposed. Microsoft Kinect v2 collects RGB and depth video information of vibrating objects in unstable ambient light. The 3DCNN-ConvLSTM architecture can effectively learn the spatial-temporal characteristics of muti-frequency vibration. The short-term spatiotemporal feature of the collected vibration information is learned through 3D convolution networks and the long-term spatiotemporal feature is learned through convolutional LSTM. Multi-modal fusion of RGB and depth mode is used to further improve the monitoring accuracy to 93% in the low frequency vibration range of 0–10 Hz. The results show that the system can monitor low frequency vibration and meet the basic measurement requirements.

scholarly journals Piezoelectric Energy Harvesting from Suspension Structures with Piezoelectric Layers

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3755 ◽  
Author(s):  
Min Wang ◽  
Yiming Xia ◽  
Huayan Pu ◽  
Yi Sun ◽  
Jiheng Ding ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Impedance Matching ◽  
Low Frequency ◽  
Single Layer ◽  
Leaf Spring ◽  
Piezoelectric Energy Harvesting ◽  
Piezoelectric Energy ◽  
Low Frequency Vibration ◽  
Piezoelectric Layers ◽  
Series Of Experiments

In this paper, we propose a generator for piezoelectric energy harvesting from suspension structures. This device consists of a leaf spring and eight pairs of piezoelectric layers attached to inner and outer surfaces. We present a special type of leaf spring, which can magnify the force from the workload to allow the piezoelectric layers to achieve larger deformation. The generator is to solve the problem of vibration energy reutilization in a low-frequency vibration system. To verify the efficiency of the proposed configuration, a series of experiments are operated. The results indicate that the resonance frequency (25.2 Hz) obtained from the sweep experiment is close to the simulation result (26.1 Hz). Impedance-matching experiments show that the sum of the output power attains 1.7 mW, and the maximum single layer reaches 0.6 mW with an impedance matching of 610 KΩ, and the instantaneous peak-peak power density is 3.82 mW/cm3. The capacitor-charging performance of the generator is also excellent under the series condition. For a 4.7 μF capacitor, the voltage is charged to 25 V in 30 s and limited at 32 V in 80 s. These results demonstrate the exploitable potential of piezoelectric energy harvesting from suspension structures.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

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