11_MAE 334Woodward - lab5

11_MAE 334Woodward - lab5 - Using the Excel Fourier...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
MAE 334 – LAB 5 11 Low Pass Filter Error Function -10 -8 -6 -4 -2 0 2 0 0.0005 0.001 0.0015 0.002 0.0025 0.003 time (sec) ln( (t)) 2. Plot the amplitude ratio in dB vs. log( f ) of your simulated filter along with the amplitude ratio in dB from Part 1 vs. log( f ). Determining the Single Pole Low Pass Filter Frequency Response Function Using Different Methods -12 -9 -6 -3 0 3 10 100 1000 10000 Frequency (Hz) Amplitude Ratio (dB) Excel Simulated Data Sine Input Method Spectral Method Figure Captions: What was the quality of your estimation of the time constant? Compare and contrast the amplitude vs. frequency curves. What errors are different in the methods that could explain the differences in the curves? Which method was the easiest? Which method would work best for a complicated transfer function? Extra Credit (Up to 25 points):
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

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....
View Full Document

This document was uploaded on 01/03/2011.

Ask a homework question - tutors are online