Vibration analysis has been conducted on large rotating machines for many decades. Proximity probes and accelerometers are traditionally used to measure bearing and shaft vibration in an effort to keep mechanical condition in check. Simple measurement of amplitude, to the more complex analysis such as Fast Fourier Transforms, are made by maintenance personnel in an effort to identify the source...

Certain pathological conditions, such as malignant tumours, manifest themselves as changes in the tissue's mechanical stiffness. This is the basis for palpation. Several techniques for imaging tissue elasticity using ultrasound have been proposed: compression elastography (strain imaging), transient elastography and vibration sonoelastography. The latter involves imaging of vibration patterns r...

This paper discusses the fault features selection using principal component analysis and using multi-class support vector machine (MSVM) for bearing faults classification. The bearings vibration signal is obtained from experiment in accordance with the following conditions: normal bearing, bearing with inner race fault, bearing with outer race fault and bearings with balls fault. Statistical pa...

A tremendous amount of research has been performed on the design and analysis of vibration energy harvester architectures with the goal of optimizing power output; most studies assume idealized input vibrations without paying much attention to whether such idealizations are broadly representative of real sources. These “idealized input signals” are typically derived from the expected nature of ...

In running cars or trains, passengers often feel sleepy. Our study focuses on this physiological phenomenon. If a machine can reproduce this phenomenon, it is feasible to put a person, such as an insomnia patient or an infant, to sleep without any harmful effects. The results of our previous study suggest that low-frequency vibration induces sleep. This report describes a new mechanical bed for...

This article presents a vibration diagnostic method designed for Permanent Magnets (PM) electrical machines–traction motors and generators. Those machines are commonly used in traction drives of electrical vehicles and small wind or water systems. The described method is very innovative and unique. Specific structural properties of machines excited by permanent magnets are used in this method e...

Many manufacturing defects could be seen in cylindrical turning. Some of these defects are: elastic deformation of work-piece, nonlinear backlash of cutting set – machine – workpiece, unknown geometry of untreated part, thermal deformations, vibration of set and machine. Deflection of workpiece under cutting forces will cause different levels of processing of workpiece 1 . Nonlinear backlash of...

Traditional methods for condition monitoring of machinery are based on detecting situations when values of features extracted form measurement data leave predetermined bands consistent with normal machine operation. Design of such systems requires considerable amounts of measurement data describing machinery failure modes that are generally very difficult to obtain due to large number of failur...

Abstract: In order to improve the intelligent diagnosis level of an on-load tap-changer’s (OLTC) mechanical condition, a feature extraction method based on variational mode decomposition (VMD) and weight divergence was proposed. The harmony search (HS) algorithm was used to optimize the parameter selection of the relevance vector machine (RVM). Firstly, the OLTC vibration signal was decomposed ...