Higher-Order Spectrum Coherent Receivers

A framework for detecting incipient wear in rotating machinery is proposed. In this paper, statistical techniques that combine power spectrum estimates with higher-order spectrum (HOS) estimates for feature development are applied to discriminate and classify vibration signals from new and slightly used drill bits in a drill wear study. Results from experimental data obtained when drilling composite circuit cards reveal that the performance of a power spectrum-based tool wear monitoring system can be enhanced by complementing the power spectrum information with HOS information on the accelerometer signal. Evidence presented supports the proposition that a HOS approach provides better signal features to a pattern classifier which allows better decisions on the state of rotating tool wear.

Download Full-text

An efficient and flexible algorithm for computing the higher order spectrum

[1992] IEEE Sixth SP Workshop on Statistical Signal and Array Processing ◽

10.1109/ssap.1992.246829 ◽

2003 ◽

Author(s):

S.C. Chan ◽

C.W. Kok

Keyword(s):

Higher Order ◽

Order Spectrum

Download Full-text

Predetermination of Higher Order Harmonics by Dual Phase Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.573.13 ◽

2014 ◽

Vol 573 ◽

pp. 13-18 ◽

Cited By ~ 1

Author(s):

V.J. Vijayalakshmi ◽

C.S. Ravichandran ◽

A. Amudha

Keyword(s):

Phase Analysis ◽

Lower Order ◽

Optimization Technique ◽

Harmonic Distortion ◽

Harmonic Spectrum ◽

Higher Order ◽

Accurate Estimation ◽

Dual Phase ◽

Order Spectrum ◽

Order Components

Previous research was mainly concentrated on eliminating the selected lower order harmonics depending on the level of inverter which was assumed to be high. The harmonics may be present even in the higher order also. The analysis of harmonic spectrum by Finite Fourier Transform yields a very accurate result for lower order harmonics. For obtaining accurate Total Harmonic Distortion (THD) value and the harmonic spectrum, inclusion of higher order harmonics is essential. The method for accurate estimation is proposed in this paper. In normal practice, the higher order harmonics present in the output of the inverter are suppressed by using filters. In order to obtain more optimized higher order harmonics, it is necessary to obtain an accurate assessment of the higher order spectrum. The higher order spectrum is predetermined by proposed technique termed as Dual Phase Analysis (DPA) so as to obtain more optimized switching angles with the application of any Optimization Technique. This is an effective tool to analyze the various higher order components of the harmonic spectrum.

Download Full-text