B2.2 - A Review of FFT Algorithms and A Real-Time Algorithm Development for Airborne Vibration Testing Applications
- Event
- ETTC 2024 - European Test and Telemetry Conference
2024-06-11 - 2024-06-13
Nuremberg - Chapter
- Data Management Applications
- Author(s)
- O. B. Ozseven - Turkish Aerospace, Istanbul (Turkey), M. Helvaci - Istanbul Technical University, Istanbul (Turkey), S. Tambova - eRC-System GmbH, Ottobrunn (Germany)
- Pages
- 181 - 194
- DOI
- 10.5162/ETTC2024/B2.2
- ISBN
- 978-3-910600-02-7
- Price
- free
Abstract
In Flight Test Instrumentation applications, many types of data are collected, including temperature, pressure, force, digital bus monitoring, etc. However, one type of data has always been popular and has become even more so with the increased use of composite structures: vibration. Vibration is a key measurement for different types of tests such as engine and propulsion system, flutter analysis, structural resonances, etc. In full-size air vehicle prototype testing, thousands or even ten thousand parameters are needed to be transformed over telemetry to the ground station. This operation itself already requires a significant amount of bandwidth in the communication channel and by considering the high-frequency behavior of vibration parameters, this situation becomes even worse. To overcome this problem, some techniques can be performed to increase the efficiency of communication by reducing the payload on the communication stream. The Fourier Transform decomposes a continuous-time signal into its foundational sinusoidal frequencies, bridging between the time and frequency domains. It reveals a signal's spectrum, denoting each frequency's strength and phase. This transformation is pivotal for understanding and isolating specific frequency components in continuous signals. The Discrete Fourier Transform (DFT) adapts the Fourier analysis to discrete-time signals, mapping a finite set of samples to a discrete frequency spectrum. It delineates the amplitudes and phases of sinusoids at distinct frequencies within digital signals. Central to digital signal processing, the DFT's efficiency is notably harnessed via the Fast Fourier Transform (FFT) algorithms. While conventional FFT algorithms are commonly favored, this paper distinguishes itself by adopting an alternative well-established method to achieve a more precise analysis in the real-time vibration analysis. In this paper, a review has been conducted to evaluate and compare well-known FFT algorithms. As a result of this review, the most efficient method has been used to solve a real-life aviation problem. The details of the problem have been given in the case-study chapter.