General Interpolated Fast Fourier Transform: A New Tool for Diagnosing Large Rotating Machinery

2004 ◽  
Vol 127 (4) ◽  
pp. 351-361 ◽  
Author(s):  
D. F. Shi ◽  
L. S. Qu ◽  
N. N. Gindy
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Gas Turbines ◽  
Transient Behavior ◽  
Rotating Machinery ◽  
Vibration Monitoring ◽  
New Approach ◽  
Maintenance Program ◽  
Window Functions ◽  
Run Up

Vibration monitoring and diagnosis of rotating machinery is an important part of a predictive maintenance program to reduce operating and maintenance costs. In order to improve the efficiency and accuracy of diagnosis, the general interpolated fast Fourier transform (GIFFT) is introduced in this paper. In comparison to present interpolated fast Fourier transform, this new approach can deal with any type of window functions and possesses high accuracy and robust performance, especially coping with a small number of sampling points. Then, for the purpose of rotating machinery diagnosis, the harmonic vibration ellipse and orbit is reconstructed based on the GIFFT to extract the features of faults and remove the interference from environmental noise and some irrelevant components. This novel scheme is proving to be very effective and reliable in diagnosing several types of malfunctions in gas turbines and compressors and characterizing of the transient behavior of rotating machinery in the run-up stage.

scholarly journals FPGA Implementation of Radix-2 based FFT Architecture for Real-Valued signal processing

2019 ◽  
Vol 8 (6) ◽  
pp. 596-601
Keyword(s):  
Signal Processing ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
High Throughput ◽  
Fpga Implementation ◽  
Low Latency ◽  
New Approach ◽  
Hardware Resource ◽  
Reversed Order

This paper investigates the various pipelined FFT architectures based on radix-2, radix-2 2 & radix-2 3 algorithms. The implemented FFTs are designed by employing techniques such as folded transform and register minimization. It maximizes the utilization of hardware resource and reduces the number of adders. It requires less area and achieves high throughput and low latency. For higher values of N, the FFT (Fast Fourier Transform) architecture has many butterfly structures which has been optimized. The FFT outputs are usually obtained in a bit reversed order and a new approach for reordering the bit-reversed orders has been proposed.

Analysis of clade shape using queueing theory and the fast Fourier transform

Paleobiology ◽  
1989 ◽  
Vol 15 (3) ◽  
pp. 321-333 ◽  
Author(s):  
Norman L. Gilinsky ◽  
I. J. Good
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Random Walks ◽  
Queueing Theory ◽  
Analytic Solution ◽  
Marine Invertebrates ◽  
New Approach ◽  
Probability Matrices ◽  
Test For Randomness ◽  
Taxonomic Groups

Using queueing theory and the fast Fourier transform, we develop a new approach to analyzing the diversity paths of fossil taxa. The methods employed focus on calculating the probabilities, for each taxonomic group, of arriving at particular values of the diversity at particular times, assuming that diversity paths are random walks. These probabilities, which are represented in probability matrices, allow us to establish a number of null hypotheses that can be used to test for randomness in the diversity paths of the taxonomic groups themselves. As the model employed here is conceptually similar to that employed by Gilinsky and Bambach (1986) in bootstrapping, one consequence of the approach is, in effect, an analytic solution of the bootstrap. A comparison of bootstrapping and analytic results in 15 taxa of marine invertebrates gives nearly identical results. The analytic approach is more general, however, and allows for the calculation of probability matrices under other model assumptions not treated here. We have also applied the probability matrices to a series of tests for nonrandomness as a whole, in contrast to the more usual method of testing particular clade statistics. The familial diversity paths of all 36 extinct orders of marine invertebrates with ten or more families were analyzed. In no case was the null hypothesis of randomness rejected at the 0.05 level. Given the model, and assuming that extinct taxa are representative of all taxa, the familial diversity paths of marine orders appear to behave as random walks.

Continuous fast Fourier transform admittance voltammetry as a new approach for studying the change in morphology of polyaniline for supercapacitors application

RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 84076-84083 ◽  
Author(s):  
J. Shabani Shayeh ◽  
P. Norouzi ◽  
M. R. Ganjali ◽  
M. Wojdyla ◽  
K. Fic ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Surface Morphology ◽  
Fast Fourier Transform ◽  
Glassy Carbon ◽  
New Approach

In this study, continuous fast Fourier transform admittance voltammetry (CFFTAV) was used to study and characterize the surface morphology of polyaniline (PANI) on glassy carbon (GC) electrodes.

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