To control underwater acoustic radiation of ships and protect against detection, coatings are attached to the vibrating wet surface of the hulls. Coatings with different pores or scatterers enclosed will attenuate vibration and suppress sound radiation with different mechanisms. However, there are very few experimental studies concerning vibration measurement of a coated structure in water, mai...

Long term exposure to high amplitude whole-body vibration is strongly associated with the development of back injury. Mobile plant used at mines are likely to be a source of high vibration amplitudes and management of the hazard requires systematic measurement of vibration levels. This paper describes measurements of whole-body vibration taken during projects funded by the Coal Services Health ...

We report a demonstration of the measurement of the ratio between an optical modulation sideband component and the nonshifted light component by time-averaged heterodyne holography in off-axis and frequency-shifting configuration, through coherent frequency-division multiplexing with a dual optical local oscillator. Experimental results of sinusoidal vibration sensing are reported. This techniq...

A primary goal of NVH engineering is the identification and control of noise and vibration sources. In recent years the torsional vibration behaviour of engine and powertrain components has gained in significance. This paper discusses several aspects of measuring and analysing torsional vibration and related data. Several torsional vibration measurement techniques are presented, together with r...

The aim is to develop vibration control of flexible spacecraft by adaptive controller. A case study will be carried out which simulates planar motion of flexible spacecraft as a coupled hybrid dynamics of rigid body motion and the flexible arm vibration. The notch filter and adaptive vibration controller, which updates filter and controller parameters continuously from the sensor measurement, a...

It is well known that a faulty gearbox vibration signal exhibits an amplitude modulation (AM) as well as a phase modulation (PM). These modulation carry out a lot of useful information about health condition. This paper presents two approaches for modeling amplitude and phase modulation in gearbox vibration signal. These last are used to describe the vibration signal by a state space model. The...

A new methodology to measure local mechatronic property of biological gel has been proposed, and measurement system has been designed with a micro-vibrating electrode. The designed system consists of two electrodes, where one of the electrodes vibrates with piezoelectric actuator. The component of variation at impedance between two electrodes with vibration of electrode is analyzed at the corre...

The largest limitation of phase-shifting interferometry for optical testing is the sensitivity to the environment, both vibration and air turbulence. In many situations the measurement accuracy is limited by the environment and sometimes the environment is sufficiently bad that the measurement cannot be performed. Recently there have been several advances in dynamic interferometry techniques fo...

A measurement bench has been developed to fully automate the procedure for the characterization of a vibration-based energy scavenging system. The measurement system is capable of monitoring all important characteristics of a vibration harvesting system (input and output voltage, current, and other parameters, frequency and acceleration values, etc.). It is composed of a PC, typical digital mea...

In this paper, we show that an atom interferometer inertial sensor, when associated with the auxiliary measurement of external vibrations, can be operated beyond its linear range and still keep a high acceleration sensitivity. We propose and compare two measurement procedures (fringe fitting and non-linear lock) that can be used to extract, without adding any bias, the mean phase of the interfe...