Reaction Wheel Disturbance Characterization by Analysis of Micro-Vibration Measurements

2012 ◽  
Vol 232 ◽  
pp. 445-449 ◽  
Author(s):  
Florian Liebold ◽  
Stephan Wiegand ◽  
Ronny Käso
Keyword(s):  
Test Bench ◽  
Vibration Test ◽  
Frequency Range ◽  
Reliable Measurement ◽  
Mechanical Oscillations ◽  
High Information Content ◽  
Micro Vibration ◽  
Production Errors ◽  
High Information

Structural stability of satellites is of vital significance for the operation of sophisticated payload systems. Therefore manufacturers of satellite components, such as reaction wheels, make huge efforts to assure the convenient vibration behavior of their products. To meet that demand a device for the detection of mechanical oscillations with very small amplitudes was developed. The described micro-vibration test-bench allows the detection of vibrations with amplitudes > 10 5 Newton in a frequency range of < 20 kHz generated by a test item with a mass up to 30 kg. The quality of the thereby obtained data makes it possible to identify the sources of the observed vibration. The high information content of the measurements originates from a set of high resolution force sensors, variably arranged on a mechanically isolated platform. The sensitivity of the used equipment (charge cables, charge amplifiers and signal analyzers) and its resistance to ambient disturbances allow the high accuracy of the measurement as mentioned above. The described micro-vibration test-bench additionally provides opportunity to detect production errors non-destructively and helps to reduce the inherent noise of the item under test. It therefore represents a reliable measurement device to quantify and assess detrimental vibrations.

scholarly journals MTG-SCA micro-vibration test bench development using linear interferometry

2017 ◽  
Author(s):  
Luis Pascual ◽  
Santiago Pasalodos ◽  
Jose Ignacio Bueno ◽  
Marcos Ubierna ◽  
Antonio Gonzalez-Elias
Keyword(s):  
Test Bench ◽  
Vibration Test ◽  
Micro Vibration

Sensitivity of a vibroacoustic signal to a change in the state of the surface layer of ceramics during frictio

2021 ◽  
pp. 141-146
Author(s):  
V. V. Kuzin ◽  
M. P. Kozochkin ◽  
S. N. Grigor’ev ◽  
S. Yu. Fedorov
Keyword(s):  
Surface Layer ◽  
Information Content ◽  
Ceramic Sample ◽  
The State ◽  
Frequency Range ◽  
Vibration Diagnostics ◽  
Vibroacoustic Signal ◽  
High Information Content ◽  
Frictional Interaction ◽  
High Information

The high information content of the vibroacoustic signal in the frequency range of 10‒16 kHz to the change in the state of the surface layer of the ceramic sample during frictional interaction with the steel disk was established. The results obtained indicate the possibility of using vibration diagnostics systems for monitoring the state of ceramic parts during operation and fi tests.

Modern Radiodiagnostics Technology of Metastasises in Pelvic Lymph Nodes

2017 ◽  
pp. 100-108
Author(s):  
V. N. Diomidova ◽  
O. A. Еfimova
Keyword(s):  
Lymph Node ◽  
Magnetic Resonance ◽  
Lymph Nodes ◽  
Metastatic Lymph Node ◽  
Magnetic Resonance Tomography ◽  
Visual Images ◽  
Pelvic Lymph Nodes ◽  
High Information Content ◽  
Pelvic Cancer ◽  
High Information

The analysis of the diagnostic informativeness of modern radiodiagnosticis methods in determining metastatic lymph node of pelvic cancer gynecological organs according to domestic and foreign publications. At the present stage methods of obtaining visual images pelvic lymph nodes are radiodiagnostics technologies (radiological, ultrasound, magnetic resonance tomography, scintigraphic). The analysis has shown that the researches devoted to diagnostic informational content of modern methods of radiodiagnosis in a differentiation of nature of damage of pelvic lymph nodes aren't enough. According to the literature, the most rational and perspective method for radiodiagnosis metastatics lymph node is a magnetic resonance imaging due to the high information content and thus specificity. At the same time, the continued relevance of further study of methods of radiodiagnostics in order to find the optimal one for the assessment of pelvic lymph nodes.

scholarly journals Development of Bench for Testing and Running-in of Slurry Pumps After Repair Activities of Drilling Equipment in the Oil and Gas Complex System

2020 ◽  
Vol 6 (1) ◽  
pp. 185-191
Author(s):  
V. Babarykin ◽  
A. Karimov ◽  
S. Kucherov ◽  
E. Evseenko ◽  
O. Gagarina
Keyword(s):  
Complex System ◽  
Oil And Gas ◽  
Test Bench ◽  
Drilling Equipment ◽  
Oil And Gas Companies

In the article the question of checking the quality of repairs carried out by slurry pumps used in drilling for oil and gas companies. Development and implementation of test bench for slurry pumps will enable the company not only to improve the reliability of the repair, but also reduce the number of repetitive equipment repairs.

Ion Beam Figuring Fabricate Effect with Different Removal Sizes

2013 ◽  
Vol 552 ◽  
pp. 142-146
Author(s):  
Yong Qiang Gu
Keyword(s):  
Spatial Frequency ◽  
Ion Beam ◽  
Influence Factors ◽  
Frequency Range ◽  
Surface Errors ◽  
Power Spectral ◽  
The Difference ◽  
Lens Surface ◽  
Ion Beam Figuring

Ion Beam Figure (IBF) is believed to be one of the most effective technics that can fabricate lens with nano or even sub-nano accuracy. For different sizes of IBF removal functions, the correct effects in different spatial frequency range are different. Power Spectral Density (PSD) curve can describe surface errors in full spatial frequency range, so it is a very convenient way to evaluate the quality of lens’ surface. In this paper, firstly, the principles of IBF and PSD are introduced briefly; Secondly, IBF removal functions with sizes from 2 mm to 15 mm are generated. A lens with surface error more than PV value 400nm is simulated with different sizes of IBF removal functions by Lucy-Richardson algorithm. Finally, experiments are done by IBF plant. A lens is fabricated by different sizes of removal functions and the fabricate results are tested by interferometer precisely and calculated to PSD curves. By the comparison of these curves, the IBF fabricate effects with different removal sizes are analyzed, which show that the smaller the removal size, the better the removal effect in higher spatial frequency range, but in the meantime, it will take a much longer time. Also the reasons of the difference between theory simulation and actual fabrication result are taken into account, and several influence factors are analyzed.

scholarly journals Investigation of intracochlear dual actuator stimulation in a scaled test rig

2017 ◽  
Vol 3 (2) ◽  
pp. 119-122
Author(s):  
Wouter J. van Drunen ◽  
Sarra Kacha Lachheb ◽  
Anatoly Glukhovskoy ◽  
Jens Twiefel ◽  
Marc C. Wurz ◽  
...  
Keyword(s):  
Low Frequency ◽  
Acoustic Stimulation ◽  
Residual Hearing ◽  
Frequency Range ◽  
Test Rig ◽  
Profound Hearing Loss ◽  
Ongoing Research ◽  
Electric Acoustic Stimulation ◽  
Single Implant

AbstractFor patients suffering from profound hearing loss or deafness still having respectable residual hearing in the low frequency range, the combination of a hearing aid with a cochlear implant results in the best quality of hearing perception (EAS – electric acoustic stimulation). In order to optimize EAS, ongoing research focusses on the integration of these stimuli in a single implant device. Within this study, the performance of piezoelectric actuators, particularly the dual actuator stimulation, in a scaled uncoiled test rig was investigated.

Sign in / Sign up

Export Citation Format

Share Document