scholarly journals Determination of the distortions introduced by the compression algorithm in the results of the measurement of the local impact control device “Prognoz-L”.

2018 ◽  
Vol 56 ◽  
pp. 02016
Author(s):  
Dmitry Migunov ◽  
Alexey Grunin
Keyword(s):  
Acoustic Emission ◽  
Control Device ◽  
Compression Algorithm ◽  
Statistical Characteristics ◽  
Pressure Monitoring ◽  
Rockburst Hazard ◽  
Automatic Mode ◽  
Signal Parameters ◽  
Local Impact

The article discusses the application of the u-law algorithm from the G.711 standard, which performs lossy compression. A theoretical error introduced by this algorithm into discrete samples of digitized acoustic emission signals is determined. The effect of compression on signal parameters was also determined. During the analysis, the data from the local "Prognoz-L" device were used. "Prognoz-L" performs rockburst hazard assessment. The data were processed in an automatic mode to isolate pulsed signals containing acoustic emission. The processing of the obtained sample of pulse signals made it possible to determine the basic statistical characteristics of the errors introduced by the compression algorithm into the values of the signal parameters. The possibility of using this algorithm for preliminary processing of acoustic emission signals is established with the aim of keeping rock pressure monitoring in low-power acoustic-emission devices.

scholarly journals Influence of Frequency and Distance on Acoustic Emission Velocity Propagating in Various Dielectrics

2020 ◽  
Vol 10 (9) ◽  
pp. 3305
Author(s):  
Daria Wotzka
Keyword(s):  
Acoustic Emission ◽  
Nonlinear Regression ◽  
Modulation Frequency ◽  
Partial Discharges ◽  
Time Of Arrival ◽  
Dielectric Liquids ◽  
Signal Parameters ◽  
Two Factors ◽  
Ae Signal

The results obtained for the measurements of acoustic emission (AE) signal parameters emitted in three dielectric liquids are presented in this paper. In particular, the velocity of AE wave was calculated based on the time of arrival of the AE signal. A frequency modulated signal was generated by a piezoelectric transducer and measured at various distances by a hydrophone. The changes in velocity values at particular distances and for different frequencies were investigated. The analyses include the determination of the dependency of the velocity values from the distance between the communicating devices. A nonlinear regression model was calculated, and the differences between AE velocities propagating in the considered dielectrics were determined. Similarly, the influence of modulation frequency on the AE velocity was determined using nonlinear regression. Based on the calculation data, it can clearly be stated that the velocity of AE wave depends significantly on the frequency and distance at which it is registered. These two factors may have an important influence on the localization of partial discharges (PD) occurring in these types of dielectric liquids.

Determination of Initial Crack Strength of Silicon Die Using Acoustic Emission Technique

2015 ◽  
Vol 44 (7) ◽  
pp. 2497-2506 ◽  
Author(s):  
Pei-Chi Chen ◽  
Yen-Fu Su ◽  
Shin-Yueh Yang ◽  
Steven Y. Liang ◽  
Kuo-Ning Chiang
Keyword(s):  
Acoustic Emission ◽  
Initial Crack ◽  
Acoustic Emission Technique

Classification of journal bearing friction states based on acoustic emission signals

2018 ◽  
Vol 85 (6) ◽  
pp. 434-442 ◽  
Author(s):  
Noushin Mokhtari ◽  
Clemens Gühmann
Keyword(s):  
Acoustic Emission ◽  
Time Domain ◽  
Journal Bearing ◽  
Prediction Method ◽  
Support Vector ◽  
Mechatronic Systems ◽  
Prediction Time ◽  
Ae Signals ◽  
Bearing Friction

Abstract For diagnosis and predictive maintenance of mechatronic systems, monitoring of bearings is essential. An important building block for this is the determination of the bearing friction condition. This paper deals with the possibility of monitoring different journal bearing friction states, such as mixed and fluid friction, and examines a new approach to distinguish between different friction intensities under several speed and load combinations based on feature extraction and feature selection methods applied on acoustic emission (AE) signals. The aim of this work is to identify separation effective features of AE signals to subsequently classify the journal bearing friction states. Furthermore, the acquired features give information about the mixed friction intensity, which is significant for remaining useful lifetime (RUL) prediction. Time domain features as well as features in the frequency domain have been investigated in this work. To increase the sensitivity of the extracted features the AE signals were transformed to the frequency-time-domain using continuous wavelet transform (CWT). Significant frequency bands are determined to separate different friction states more effective. A support vector machine (SVM) is used to classify the signals into three different friction classes. In the end the idea for an RUL prediction method by using the already determined information is given and explained.

The Study of Fuel-Saving Technology of GSI

2014 ◽  
Vol 1070-1072 ◽  
pp. 392-397
Author(s):  
Jun Hui Xu ◽  
Ming Qiu Gao ◽  
Ji Qiang Gao ◽  
Xiang Bao
Keyword(s):  
Fuel Consumption ◽  
Fuel Economy ◽  
Rolling Resistance ◽  
Fuel Saving ◽  
Pressure Monitoring ◽  
Tire Pressure ◽  
Engine Efficiency ◽  
Tire Pressure Monitoring System ◽  
The Eu

In the background of the main technologies of fuel economy in automobiles developed to a certain stage, it is necessary to reduce fuel consumption and increase the engine efficiency by developing other auxiliary technologies such as improving the ratio of pure energy drive, low rolling resistance tires, tire pressure monitoring system and gear shift indicators (GSI). This article introduces the principle of GSI, analyses how GSI works in improving engine efficiency, and then evaluates the method for determination of the relative saving rate of fuel consumption, which method was introduced in the EU regulation EC No. 65/2012.

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