Piezoelectric acceleration sensors based on LGX and ReCOB crystals for application above 645ºC

Author(s):  
Yanqing Zheng ◽  
Xiaoniu Tu ◽  
Jianjun Chen ◽  
Pan Gao ◽  
Erwei Shi
2014 ◽  
Vol 536-537 ◽  
pp. 320-324
Author(s):  
Deng Hua Li ◽  
Cui Hao

Although piezoelectric acceleration sensors enclosure can shield electromagnetic pulse commendably, the electromagnetic pulse can be coupled into the sensor and interfere signal processing circuit in the high-frequency electromagnetic environment, which can lead to the failure of acceleration sensor. So, the reasonable design and optimization are necessary for the improvement of signal processing circuit anti-electromagnetic interference ability under the principle of EMC. Some methods were proposed in this paper, such as adding a filter circuit, increasing the spacing between the wires and increasing the number of ground wires, etc. Finite integration technique (FIT) is used in this paper for these simulations in CST software. Simulating results show that the transfer impedances of signal processing circuit under the high-frequency electromagnetic interference were greatly reduced after optimization and power integrity was greatly improved. It achieves the goal of enhancing electromagnetic interference resistance of the signal processing circuit, thereby reduces the influence of the electromagnetic pulse on the piezoelectric acceleration sensor greatly.


2018 ◽  
Vol 8 (9) ◽  
pp. 1621 ◽  
Author(s):  
Fan Jiang ◽  
Zhencai Zhu ◽  
Wei Li ◽  
Yong Ren ◽  
Gongbo Zhou ◽  
...  

Acceleration sensors are frequently applied to collect vibration signals for bearing fault diagnosis. To fully use these vibration signals of multi-sensors, this paper proposes a new approach to fuse multi-sensor information for bearing fault diagnosis by using ensemble empirical mode decomposition (EEMD), correlation coefficient analysis, and support vector machine (SVM). First, EEMD is applied to decompose the vibration signal into a set of intrinsic mode functions (IMFs), and a correlation coefficient ratio factor (CCRF) is defined to select sensitive IMFs to reconstruct new vibration signals for further feature fusion analysis. Second, an original feature space is constructed from the reconstructed signal. Afterwards, weights are assigned by correlation coefficients among the vibration signals of the considered multi-sensors, and the so-called fused features are extracted by the obtained weights and original feature space. Finally, a trained SVM is employed as the classifier for bearing fault diagnosis. The diagnosis results of the original vibration signals, the first IMF, the proposed reconstruction signal, and the proposed method are 73.33%, 74.17%, 95.83% and 100%, respectively. Therefore, the experiments show that the proposed method has the highest diagnostic accuracy, and it can be regarded as a new way to improve diagnosis results for bearings.


1995 ◽  
Vol 5 (4) ◽  
pp. 282-288 ◽  
Author(s):  
A Hariz ◽  
H G Kim ◽  
M R Haskard ◽  
I J Chung

1968 ◽  
Vol 2 (4) ◽  
pp. 311-317
Author(s):  
V.M. Gusev ◽  
V.A. Kislyakov ◽  
M.M. Levashov ◽  
I.V. Orlov ◽  
R.I. Polonnikov

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Heikki Hyyti ◽  
Arto Visala

An attitude estimation algorithm is developed using an adaptive extended Kalman filter for low-cost microelectromechanical-system (MEMS) triaxial accelerometers and gyroscopes, that is, inertial measurement units (IMUs). Although these MEMS sensors are relatively cheap, they give more inaccurate measurements than conventional high-quality gyroscopes and accelerometers. To be able to use these low-cost MEMS sensors with precision in all situations, a novel attitude estimation algorithm is proposed for fusing triaxial gyroscope and accelerometer measurements. An extended Kalman filter is implemented to estimate attitude in direction cosine matrix (DCM) formation and to calibrate gyroscope biases online. We use a variable measurement covariance for acceleration measurements to ensure robustness against temporary nongravitational accelerations, which usually induce errors when estimating attitude with ordinary algorithms. The proposed algorithm enables accurate gyroscope online calibration by using only a triaxial gyroscope and accelerometer. It outperforms comparable state-of-the-art algorithms in those cases when there are either biases in the gyroscope measurements or large temporary nongravitational accelerations present. A low-cost, temperature-based calibration method is also discussed for initially calibrating gyroscope and acceleration sensors. An open source implementation of the algorithm is also available.


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