scholarly journals Characteristic Parameter Optimization of Wireless Flaw Sensing System Based on Active Interference Suppression Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wenping Wu
Keyword(s):  
Frequency Modulation ◽  
Interference Suppression ◽  
Spectral Characteristics ◽  
Measurement Data ◽  
Characteristic Parameter ◽  
Interference Signal ◽  
Simulation Platform ◽  
Actual Measurement ◽  
Modulation Parameter ◽  
Harmonic Components

Based on the active interference suppression algorithm, this study combines the radar working mode and the interference type and realizes the effective detection of the flaw detection signal by successively processing the radar receiving signal and the filtering processing. Firstly, this article builds a simulation platform similar to the actual situation to verify the existing conventional active interference suppression algorithms. Secondly, for the detection of chirp active deception jamming signals entering from the main lobe, a radar active deception jamming detection method based on the characteristic parameter matching of the harmonic components of active deception jamming signals is proposed. After that, the spectral characteristics of the harmonic components of the deception interference signal are analyzed, and the center frequency and the tuning frequency of the real target echo are obtained. Finally, by establishing a frequency modulation parameter library for possible interference harmonic signal components, the acquisition phase of the radar gate by the jammer matched analysis with the preestablished frequency modulation parameter library is implemented to achieve active deception interference detection. This method can effectively detect active deception jamming signals in a complex tunnel environment. The interference suppression algorithms verified by simulation include noise FM interference suppression algorithm based on cancellation and distance false target interference suppression algorithm based on LFM radar summary processing. Through actual measurement data processing and analysis, the effectiveness of the method is verified and the idea of interference suppression is expanded. The construction of the simulation platform is obtained by appropriately modifying the actual parameters, a certain type of suppression jammer, and a certain type of deception jammer used in a certain countermeasure field test at a radar station.

scholarly journals Development of Three-Phase Permanent-Magnet Synchronous Motor Drive with Strategy to Suppress Harmonic Current

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1583
Author(s):  
Wei-Tse Kao ◽  
Jonq-Chin Hwang ◽  
Jia-En Liu
Keyword(s):  
Permanent Magnet ◽  
Electromotive Force ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Motor Drive ◽  
Actual Measurement ◽  
Current Harmonic ◽  
Three Phase ◽  
Measurement Results ◽  
Harmonic Components

This study aimed to develop a three-phase permanent-magnet synchronous motor drive system with improvement in current harmonics. Considering the harmonic components in the induced electromotive force of a permanent-magnet synchronous motor, the offline response of the induced electromotive force (EMF) was measured for fast Fourier analysis, the main harmonic components were obtained, and the voltage required to reduce the current harmonic components in the corresponding direct (d-axis) and quadrature (q-axis) axes was calculated. In the closed-loop control of the direct axis and quadrature axis current in the rotor reference frame, the compensation amount of the induced EMF with harmonic components was added. Compared with the online adjustment of current harmonic injection, this simplifies the control strategy. The drive system used a 32-bit digital signal processor (DSP) TMS320F28069 as the control core, the control strategies were implemented in software, and a resolver with a resolver-to-digital converter (RDC) was used for the feedback of angular position and speed. The actual measurement results of the current harmonic improvement control show that the total harmonic distortion of the three-phase current was reduced from 5.30% to 2.31%, and the electromagnetic torque ripple was reduced from 15.28% to 5.98%. The actual measurement results verify the feasibility of this method.

Dynamic Measurement of Spatial Attitude at Bottom Rotating Drillstring: Simulation, Experimental, and Field Test

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Qilong Xue ◽  
Ruihe Wang ◽  
Baolin Liu ◽  
Leilei Huang
Keyword(s):  
Real Time ◽  
Measurement Errors ◽  
Time Window ◽  
Measurement Data ◽  
Movement Patterns ◽  
Dynamic Measurement ◽  
Drilling Process ◽  
Stick Slip ◽  
Actual Measurement ◽  
Gas Drilling

In the oil and gas drilling engineering, measurement-while-drilling (MWD) system is usually used to provide real-time monitoring of the position and orientation of the bottom hole. Particularly in the rotary steerable drilling technology and application, it is a challenge to measure the spatial attitude of the bottom drillstring accurately in real time while the drillstring is rotating. A set of “strap-down” measurement system was developed in this paper. The triaxial accelerometer and triaxial fluxgate were installed near the bit, and real-time inclination and azimuth can be measured while the drillstring is rotating. Furthermore, the mathematical model of the continuous measurement was established during drilling. The real-time signals of the accelerometer and the fluxgate sensors are processed and analyzed in a time window, and the movement patterns of the drilling bit will be observed, such as stationary, uniform rotation, and stick–slip. Different signal processing methods will be used for different movement patterns. Additionally, a scientific approach was put forward to improve the solver accuracy benefit from the use of stick–slip vibration phenomenon. We also developed the Kalman filter (KF) to improve the solver accuracy. The actual measurement data through drilling process verify that the algorithm proposed in this paper is reliable and effective and the dynamic measurement errors of inclination and azimuth are effectively reduced.

Blade Fault Recognition Based on Signal Processing and Adaptive Fluid Dynamic Modelling

1997 ◽  
Author(s):  
A. Stamatis ◽  
N. Aretakis ◽  
K. Mathioudakis
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Measurement Data ◽  
Dynamic Modelling ◽  
Physical Modelling ◽  
Diagnostic Procedures ◽  
Measured Quantity ◽  
Test Cases ◽  
Actual Measurement ◽  
Fault Recognition

An approach for identification of faults in blades of a gas turbine, based on physical modelling is presented. A measured quantity is used as an input and the deformed blading configuration is produced as an output. This is achieved without using any kind of “signature”, as is customary in diagnostic procedures for this kind of faults. A fluid dynamic model is used in a manner similar to what is known as “inverse design methods”: the solid boundaries which produce a certain flow field are calculated by prescribing this flow field. In the present case a signal, corresponding to the pressure variation on the blade-to-blade plane, is measured. The blade cascade geometry that has produced this signal is then produced by the method. In the paper the method is described and applications to test cases are presented. The test cases include theoretically produced faults as well as experimental cases, where actual measurement data are shown to produce the geometrical deformations which existed in the test engine.

scholarly journals Evaluating the Accuracy of Railway Total Simulator Compared with Actual Measurement Data

2018 ◽  
Vol 7 (5) ◽  
pp. 416-424
Author(s):  
Tsutomu Miyauchi ◽  
Kenji Imamoto ◽  
Keiko Teramura ◽  
Hirotaka Takahashi
Keyword(s):  
Measurement Data ◽  
Actual Measurement

Application of Entropy-Weight Hierarchy Analysis on Study of Height Prediction of Water Conducted Zone

2013 ◽  
Vol 742 ◽  
pp. 497-500
Author(s):  
Meng Lin Xu ◽  
De Shen Zhao
Keyword(s):  
Analytic Hierarchy Process ◽  
Measurement Data ◽  
Entropy Weight ◽  
Analytic Hierarchy ◽  
Actual Measurement ◽  
Entropy Weight Method ◽  
Hierarchy Analysis ◽  
Height Prediction ◽  
Weight Method ◽  
Hierarchy Process

Based on actual measurement data in Da Ping as the samples,according to the experience, and ends with calculate every factors weight and height prediction of the water conducted zone by Matlab using the combination entropy-weight method and analytic hierarchy process. this paper introduces a comprehensive prediction model consisting of analytic hierarchy process and combination entropy-weight method. The method,overcoming weights imbalance,gives the evaluation result better than does the single analytic hierarchy process, it is a new valid method for scientific forecast on water conducted zone.

scholarly journals Diagnostic Procedures for Jet Engines

1985 ◽  
Author(s):  
R. Lunderstädt ◽  
K. Fiedler
Keyword(s):  
Mathematical Model ◽  
Path Analysis ◽  
Working Conditions ◽  
Measurement Data ◽  
Diagnostic Procedures ◽  
Practical Significance ◽  
Jet Engines ◽  
Actual Measurement ◽  
Jet Engine ◽  
The Mathematical Model

In the paper to be presented diagnostic procedures on the basis of a gas path analysis are applied on a two-shaft jet engine. Starting from the mathematical model of the engine a filter-algorithm is used which delivers from actual measurement data the state of the engine for different working conditions. The procedure is proven for some examples and discussed in regard of its practical significance.

scholarly journals Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

2020 ◽  
Author(s):  
Xiaoyu Wang ◽  
Peng Liu ◽  
Gongwen Xu
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Measurement Data ◽  
Ground Temperature ◽  
Rapid Urbanization ◽  
Actual Measurement ◽  
Heritage Sites ◽  
Human Thermal Comfort ◽  
The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

scholarly journals High Dimensional Electromagnetic Interference Signal Clustering Based On SOM Neural Network

2016 ◽  
Vol 20 (1) ◽  
pp. 27
Author(s):  
Hongyi Li ◽  
Di Zhao ◽  
Shaofeng Xu ◽  
Pidong Wang ◽  
Jiaxin Chen
Keyword(s):  
Neural Network ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Spectral Characteristics ◽  
Simulation Models ◽  
Integrated System ◽  
Interference Signal ◽  
Global Features ◽  
Strongly Nonlinear ◽  
Emc Design

In this paper, we study the spectral characteristics and global representations of strongly nonlinear, non-stationary electromagnetic interferences (EMI), which is of great significance in analysing the mathematical modelling of electromagnetic capability (EMC) for a large scale integrated system. We firstly propose to use Self-Organizing Feature Map Neural Network (SOM) to cluster EMI signals. To tackle with the high dimensionality of EMI signals, we combine the dimension reduction and clustering approaches, and find out the global features of different interference factors, in order to finally provide precise mathematical simulation models for EMC design, analysis, forecasting and evaluation. Experimental results have demonstrated the validity and effectiveness of the proposed method.

The Application of a Linear FM Interference Suppression in DSSS Technology Systems

2014 ◽  
Vol 644-650 ◽  
pp. 4599-4602
Author(s):  
Gang Fu ◽  
Jian Hua Lin ◽  
Qian He
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Interference Suppression ◽  
Direct Sequence Spread Spectrum ◽  
Signal Interference ◽  
Interference Signal ◽  
Direct Sequence ◽  
Research Focus ◽  
Wideband Interference ◽  
Suppression Technique

Spread spectrum communication system wideband interference suppression technique has drawn increasing attention. In this paper, the typical broadband interference signal interference LFM (Linear Frequency-Modulated, LFM), for example, the results of research focus and reviews the current direct sequence spread spectrum (Direct Sequence Spread Spectrum, DSSS) system wideband interference suppression.

In Vitro Physical and Biological Evaluations of a 2.4 GHz Electromagnetic Exposure Setup

2021 ◽  
Vol 36 (1) ◽  
pp. 82-88
Author(s):  
Mengxi Wang ◽  
Guohui Yang ◽  
Yu Li ◽  
Qun Wu
Keyword(s):  
Electromagnetic Radiation ◽  
Specific Absorption Rate ◽  
Measurement Data ◽  
Energy Coupling ◽  
Fdtd Simulation ◽  
Biological Experiment ◽  
Actual Measurement ◽  
Physical Test ◽  
Polarization Characteristics

In this paper, a 2.4 GHz electromagnetic radiation system for cells in vitro was designed from the perspective of optimal energy coupling of cell samples. The validity of the design was verified by FDTD simulation, physical test and biological experiment. The electromagnetic parameters of SAR (Specific Absorption Rate) and temperature rise were obtained by FDTD simulation. The validation of temperature simulation was confirmed by comparing the actual measurement data and the simulation data. The SAR relative uniformity between samples was tested by cell biological experiment, in which ROS (Reactive Oxygen Species), a typical and sensitive biological parameter reacting to electromagnetic radiation in cells, of different sample dishes induced by 2.4 GHz electromagnetic radiation with an incident power of 0.5 W was analyzed. We found that the size of cell dish affects the energy coupling intensity, the polarization characteristics of electromagnetic wave determines the distribution pattern of SAR, and the uniformity of sample energy absorption in this radiation system is good.

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