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.

Low-Frequency Vibration Measurement Based on Spatiotemporal Analysis of Shadow Moiré

2011 ◽  
Vol 31 (4) ◽  
pp. 0412005
Author(s):  
史红健 Shi Hongjian ◽  
朱飞鹏 Zhu Feipeng ◽  
何小元 He Xiaoyuan
Keyword(s):  
Low Frequency ◽  
Spatiotemporal Analysis ◽  
Vibration Measurement ◽  
Shadow Moire ◽  
Shadow Moiré ◽  
Low Frequency Vibration

scholarly journals Low-frequency vibration measurement by a dual-frequency DBR fiber laser

2017 ◽  
Vol 7 (3) ◽  
pp. 206-210 ◽  
Author(s):  
Bing Zhang ◽  
Linghao Cheng ◽  
Yizhi Liang ◽  
Long Jin ◽  
Tuan Guo ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Frequency ◽  
Vibration Measurement ◽  
Dual Frequency ◽  
Low Frequency Vibration

Constrained Design Optimization of Vibration Energy Harvesting Devices

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Mehdi Hendijanizadeh ◽  
Mohamed Moshrefi-Torbati ◽  
Suleiman M. Sharkh
Keyword(s):  
Energy Harvesting ◽  
Low Frequency ◽  
Load Resistance ◽  
Relative Displacement ◽  
Internal Resistance ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Optimum Load ◽  
Seismic Mass ◽  
Low Frequency Vibration

Existing design criteria for vibration energy harvesting systems provide guidance on the appropriate selection of the seismic mass and load resistance. To harvest maximum power in resonant devices, the mass needs to be as large as possible and the load resistance needs to be equal to the sum of the internal resistance of the generator and the mechanical damping equivalent resistance. However, it is shown in this paper that these rules produce suboptimum results for applications where there is a constraint on the relative displacement of the seismic mass, which is often the case. When the displacement is constrained, increasing the mass beyond a certain limit reduces the amount of harvested power. The optimum load resistance in this case is shown to be equal to the generator's internal resistance. These criteria are extended to those devices that harvest energy from a low-frequency vibration by utilizing an interface that transforms the input motion to higher frequencies. For such cases, the optimum load resistance and the corresponding transmission ratio are derived.

A Six Degrees-of-Freedom Vibration Isolation Platform Supported by a Hexapod of Quasi-Zero-Stiffness Struts

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Jiaxi Zhou ◽  
Kai Wang ◽  
Daolin Xu ◽  
Huajiang Ouyang ◽  
Yingli Li
Keyword(s):  
Degrees Of Freedom ◽  
Vibration Isolation ◽  
Permanent Magnets ◽  
Low Frequency ◽  
Harmonic Balance Method ◽  
Dynamic Responses ◽  
Six Degrees Of Freedom ◽  
Low Frequency Vibration ◽  
Force Moment ◽  
Vibration Isolation Performance

A platform supported by a hexapod of quasi-zero-stiffness (QZS) struts is proposed to provide a solution for low-frequency vibration isolation in six degrees-of-freedom (6DOFs). The QZS strut is developed by combining a pair of mutually repelling permanent magnets in parallel connection with a coil spring. Dynamic analysis of the 6DOFs QZS platform is carried out to obtain dynamic responses by using the harmonic balance method, and the vibration isolation performance in each DOF is evaluated in terms of force/moment transmissibility, which indicates that the QZS platform perform a good function of low-frequency vibration isolation within broad bandwidth, and has notable advantages over its linear counterpart in all 6DOFs.

Research on Magnetoelectric Seismometer's Low Frequency Extension Technology

2014 ◽  
Vol 664 ◽  
pp. 268-273
Author(s):  
Yun Tian Teng ◽  
Xing Xing Hu ◽  
Hong Ya Lu
Keyword(s):  
Frequency Response ◽  
Low Cost ◽  
Low Frequency ◽  
High Sensitivity ◽  
Inertial Mass ◽  
Negative Resistance ◽  
Low Noise ◽  
Corner Frequency ◽  
Filter Method ◽  
High Frequency Response

Magnetoelectric seismometer has many outstanding features, such as low cost, small size, light weight, high sensitivity, low noise, good high frequency response, and reliable operation, simple set up, so these type of seismometer is widely used in several areas. However, because the structure of magnetoelectric seismometer (inertial mass and elastic support module), there has the material and mechanical structure limitation, so the inherent frequency is around between 5 to 30Hz, hard to be lower, hence, the low frequency characteristic is poor. To extend the seismometer's range of application, post compensation is needed. The researchers from both home and aboard proposed many different method to deal with the low frequency response of this seismometer, such as “inverse filter” method, “Lippmann” method, which uses negative resistance and feedback coil. These methods have got some results separately. In this paper, we will propose a low frequency integral method to extend the seismometer's frequency response. It is accomplished through balanced integration and high precision chips to suppress the circuit drifting and noise interference. The results from vibration table shows, after integration, the seismometer's low frequency corner frequency is extended from 2 Hz to under 0.1 Hz, the sensitivity is enhanced from 200V/m·s-1 to 400V/m·s-1.

Fiber Bragg Grating Accelerometer Based on L-Shaped Rigid Beam and Elastic Diaphragm for Low-Frequency Vibration Measurement

2015 ◽  
Vol 35 (12) ◽  
pp. 1206005 ◽  
Author(s):  
曾宇杰 Zeng Yujie ◽  
王俊 Wang Jun ◽  
杨华勇 Yang Huayong ◽  
马丽娜 Ma Lina
Keyword(s):  
Fiber Bragg Grating ◽  
Low Frequency ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Low Frequency Vibration
Sign in / Sign up

Export Citation Format

Share Document