Diffusion tensor imaging is widely used in research and clinical applications, but still suffers from substantial artifacts. Here, we focus on vibrations induced by strong diffusion gradients in diffusion tensor imaging, causing an echo shift in k-space and consequential signal-loss. We refined the model of vibration-induced echo shifts, showing that asymmetric k-space coverage in widely used P...

The vibration signal obtained from operating machines contains information relating to machine condition as well as noise. Further processing of the signal is necessary to elicit information particularly relevant to bearing faults. Many techniques have been employed to process the vibration signals in bearing faults detection and diagnosis. Two common techniques, time domain techniques and freq...

Based on the existing dual-stage control scheme for hard disk drives, this paper focuses on the design and analysis of adaptive feedforward control of airflow induced suspension vibration, which utilizes the vibration signal obtained from instrumented suspension. In this scheme, a strain signal on the surface of the instrumented suspension is obtained which is indicative of the suspension’s vib...

This paper presents a new approach to machine health monitoring based on the Approximate Entropy (ApEn), which is a statistical measure that quantifies the regularity of a time series, such as vibration signals measured from an electrical motor or a rolling bearing. As the working condition of a machine system deteriorates due to the initiation and/or progression of structural defects, the numb...

The diagnosis of gearbox faults based on the Fourier analysis of the vibration signal produced from a gear reductor system has proved its limitations in terms of spectral resolution. In this paper, we propose a method for the fault diagnosis of a gear reductor made of two toothed wheels operating at constant conditions. This technique is based on Prony method. The good performances of the propo...

Comparing with fixed shaft gearbox, vibration properties of planetary gearbox are much more complicated. In a planetary gearbox, there are multiple vibration sources as several pairs of sun-planet gears and several pairs of ringplanet gears mesh simultaneously. In addition, the signal transmission path changes due to the rotation of the carrier. To facilitate fault detection of a planetary gear...

In recent years, the use of wireless sensor networks for vibration monitoring is emphasized, because of its capability to continuously monitor at hard-to-reach locations of complex machines. Low power consumption is one of the main requirements for the sensor nodes in continuous and long-term vibration monitoring. However, the power consumption of state-of-the-art wireless sensor nodes is signi...

In this paper, a hybrid technique is proposed for detecting the vibration signal of electric motor. The proposed hybrid technique is the combination of S-transformation algorithm and radial basis function neural network (RBFNN) technique. Initially, the pre-processing is applied in the electric motor signal such as normal and vibration. Then, the features of the signal are extracted by using S-...

With increased system complexity, Condition-Based Maintenance (CBM) becomes a promising solution to system safety by detecting faults and scheduling maintenance procedures before faults become severe failures resulting in catastrophic events. For CBM of many mechanical systems, fault diagnosis and failure prognosis based on vibration signal analysis are essential techniques. Noise originating f...

The goal of this article is to assess the feasibility of estimating the state of various rotating components in agro-industrial machinery by employing just one vibration signal acquired from a single point on the machine chassis. To do so, a Support Vector Machine (SVM)-based system is employed. Experimental tests evaluated this system by acquiring vibration data from a single point of an agric...