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Unformatted text preview: Using the Excel Fourier Analysis tool pack add-in or MatLab perform a Fourier Transform on your step input and step input response functions. Start the transform very close to the start of the step input. Add extra points to the end of your data set by repeating the last response value and calculating the time column so you can perform a 1024 FFT. 1. Plot the magnitude in dB of the FFT vs. frequency in Hertz. Normalize the magnitude by the first non-zero frequency point in the FFT. (The very first point in the FFT output is the DC, zero frequency, point) See the example spreadsheet. This will not produce the true transfer function because the magnitude ratio should be calculated using the transform of the input signal....
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This document was uploaded on 01/03/2011.
- Spring '09