The suitable condition of an onload tap changer (OLTC) is essential for the operation a power transformer. It extremely desirable to have some indicators assess OLTC condition, especially if these are capable being used in online monitoring system that does not affect normal This paper describes methodology by using envelope analysis based on Hilbert transform and orthogonal decomposition wavelet determine main diagnostic parameters transformer assessment means vibration measurements during...

An onload tap changer (OLTC) in suitable conditions is essential for the operation of a power transformer. It extremely desirable to have indicators that help assess OLTC, especially if these can be used an on-line monitoring system does not affect normal This paper describes method detecting faults selector by means vibration measurements during operation, using envelope analysis based on Hilbert transform and wavelet decomposition. Different failures at distinguished signature as they are...

Wavelet transform (WT) has been used in the diagnosis of cracked rotors since 1990s. At present, WT is one most commonly tools to treat signals several fields. Understandably, this an area extensive scientific research, which why paper aims summarize briefly major advances field 2008. The present review considers use and application WT, selection parameters used, key achievements using for crack diagnosis.

An efficient maintenance is a key consideration in systems of railway transport, especially high-speed trains, order to avoid accidents with catastrophic consequences. In this sense, having method that allows for the early detection defects critical elements, such as bogie mechanical components, crucial increasing availability rolling stock and reducing costs. The main contribution work proposal methodology that, based on classical signal processing techniques, provides set parameters fast...

Crack detection for railway axles is key to avoiding catastrophic accidents. Currently, non-destructive testing used that purpose. The present work applies vibration signal analysis diagnose cracks in real installed on a Y21 bogie working rig. Vibration signals were obtained from two wheelsets with at the middle section of axle depths 5.7 15 mm, several conditions load and speed. processed by means wavelet packet transform energy. Energies train an artificial neural network, reliable...

Railway axles are critical to the safety of railway vehicles. However, axle maintenance is currently based on scheduled preventive using Nondestructive Testing. The use condition monitoring techniques would provide information about status between periodical inspections, and it be very valuable in prevention catastrophic failures. Nevertheless, literature, there not many studies focusing this area a lack experimental data. In work, reliable real-time condition-monitoring technique for...

In this paper, a new detection and classification system of faulty bearings is presented. This based on artificial intelligent techniques vibration signals in the frequency domain produced by bearings. The consists several neuro-fuzzy systems cascade, along with measurement equipment for spectral data. These have been used as bi-classifiers. That is, each specialized between two different types rolling bearing status. A careful selection process rules has included learning algorithm....

In the maintenance of motor driven systems, detection cracks in shafts play a critical role. Condition monitoring and fault diagnostics detect distinguish different kinds machinery faults, provide significant improvement efficiency. this study, we apply discrete wavelet transform theory multiresolution analysis (MRA) to vibration signals find characteristic patterns with transversal crack. The feature vectors generated are used as input an intelligent classification system based on...

Several models exist for calculating superconducting repulsion forces in the Meissner state that are based on method of images. The images, however, is limited to a small number geometrical configurations can be solved exactly, and physical interpretation under discussion. A general local model London equations Maxwell’s has been developed describe mechanics superconductor-permanent magnet system. Due its differential form, this expression easily implemented finite elements analysis and,...

A quasi-passive biped (having only one actuator) developed into a Spanish project called "PASIBOT" [1] is presented in this article.We focus on the PASIBOT's topology, kinematics and dynamics, we describe program designed for carrying out corresponding calculations.This code provides all kinematic dynamic data, as functions of time, along step: position, velocity acceleration members, well forces torques each them, motor torque included.This latter information has helped us to choose...

Abstract This paper describes the development and assessment of a Native Android App for learning concepts related with Mechanical Engineering. The designed App, called MaqTest , is an interactive, easy to use portable tool. proposed application has been programmed Studio, it presented as executable file accessible smartphones tablets. It allows student auto‐evaluate conceptual understandings, increasing their level knowledge enhancing academic results. app test students 3rd course...

This article addresses the supporting foot slippage of biped robot PASIBOT and develops its forward inverse dynamics for simple double support phases. To address phenomenon, we consider an additional degree freedom at also distinguish between static kinetic friction conditions. The dynamics, accounting slippage, are encoded in MATLAB. algorithm predicts motion from torque function given by biped's sole motor. Thus, becomes indispensable tool studying transient states (for example, torques...

The goal of this article is to design a navigation algorithm improve the capabilities an all-terrain unmanned ground vehicle by optimizing its configuration (the angles between legs and body) for given track profile function. function can be defined either numerical equations or points. body varied in order adaptation profiles. A new dynamic model unstructured environments has been presented. based on half-vehicle quasi-static approach relates variables interest with topology mechanism....

Input shaping is an Optimal Control feedforward strategy whose ability to define how and when a flexible dynamical system defined by Ordinary Differential Equations (ODEs) computer controlled would move into its operative space, without command induced unwanted dynamics, has been exhaustively demonstrated. This work examines the issue of Embedded Internet Things (IoT) Shaping with regard real time control multibody oscillatory systems dynamics are better described differential algebraic...