A new approach for fault identification in computer networks

2004 ◽  
Author(s):  
Dong Zhao ◽  
Tao Wang
Keyword(s):  
Computer Networks ◽  
Fault Identification ◽  
New Approach

Fault Identification in Non-Stationary Systems Based on Sliding Mode Observers

2021 ◽  
Vol 22 (12) ◽  
pp. 625-633
Author(s):  
A. V. Zuev ◽  
A. N. Zhirabok ◽  
V. F. Filaretov ◽  
A. A. Protsenko
Keyword(s):  
Canonical Form ◽  
Sliding Mode ◽  
Original System ◽  
Matching Condition ◽  
Observer Design ◽  
Fault Identification ◽  
New Approach ◽  
Minimal Dimension ◽  
Sliding Mode Observers ◽  
Traditional Approaches

The paper is devoted to the problem of fault identification in technical systems described by non-stationary nonlinear dynamic equations under unmatched disturbances. To solve the problem, sliding mode observers are used. The suggested ap- proach is based on the model of the original system of minimal dimension having different sensitivity to the faults and distur- bances in contrast to the traditional approaches to sliding observer design which are based on the original system. Additionally it is assumed that matrices describing such a model have the canonical form and are constant. The main purpose of using such a model is possibility to take into account the non-stationary feature of the systems. As a result, the model has stationary dynamic and non-stationary additional term that allows to promote sliding mode design. Besides, the new approach to design sliding mode observers is suggested. The peculiarity of this approach is that it does not require that original systems should be minimum phase and detectable. According to the traditional approaches stability of the observer is provided by minimum phase and detectability properties. In our approach, stability of the observer is achieved due to the canonical form of the matrices describing the model. In addition, the matching condition is not necessary. This allows to extend a class of systems for which sliding mode observers can be designed. Theoretical results are illustrated by practical example of electric servoactuator.

Broken Rotor Bar Detection Using High Frequency Loss Calculation of Induction Motor

2014 ◽  
Vol 573 ◽  
pp. 728-733
Author(s):  
I. Kathir ◽  
S. Balakrishnan ◽  
B.V. Manikandan
Keyword(s):  
Flux Density ◽  
High Frequency ◽  
Induction Motors ◽  
Fault Identification ◽  
New Approach ◽  
Broken Rotor Bar ◽  
Finite Element Software ◽  
Loss Calculation ◽  
Squirrel Cage ◽  
Three Phase

This paper proposes a technique for the identification of defects of three-phase squirrel cage induction motors. Simulations were performed using ANSYS finite element software package to obtain the flux density waveform in the air gap. Broken rotor bar fault was simulated by breaking rotor bars to see how the flux density is affected. In this paper, a new approach for the identification of broken rotor bar based on the calculation of high-frequency losses in induction motors is presented. The approach presented in this paper requires little time for loss calculation and fault identification.

scholarly journals Faults Detection and Classification under Variable Condition Using Intrinsic Time - Scale Decomposition and Neural Network

2021 ◽  
Vol 54 (5) ◽  
pp. 777-782
Author(s):  
Saidani Djama Leddine ◽  
Rahmoune Chamceddine ◽  
Zenasni Ramdane
Keyword(s):  
Time Scale ◽  
Fault Identification ◽  
Multilayer Network ◽  
Vibration Signals ◽  
New Approach ◽  
Intrinsic Time ◽  
System A ◽  
Average Accuracy ◽  
Time Scale Decomposition ◽  
Variable Condition

Misalignment and unbalance are a common fault occurring in the rotor system. A new approach for detecting misalignment and unbalance problems combining the intrinsic time - scale decomposition (ITD), the root mean square (RMS) and perceptron multilayer network (MLP) is proposed in this paper. Vibration signals of normal condition, misalignment horizontal, misalignment vertical and unbalance with different level are collected under different speed. ITD, nonlinear analysis of signals, was applied to decompose the vibration signals into 8 proper rotation components. The RMS values of 8 components are calculated and using as features vector. Last, the perceptron multilayer network was used for fault identification and classification. The proposed approach accurately classified and detection of unbalance and misalignment; the average accuracy achieved is 97.99%.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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