DAQ Homework
daq_hw.pdf (75.211 Kb)Fourier Homework
Example on how to read in data using Python (0.286 Kb)Fourier HW 1 (24.906 Kb)
Fourier HW 2 (24.978 Kb)
Determine expressions for y(t) based on taking the FFT of the data. Data is tab delimited in 2 columns - t and y(t). Verify your expression for y(t) by plotting your expression over top of the data from the file.
Be sure to clearly label your plots and submit your code.
Due Friday 9/22.
Python users can load data from text files using this command (from scipy in ipython):
data=io.read_array('fourier_hw1.txt',separator='\t')#read data from file (tab-delimited)
#Note: Python always counts from 0 for indices
data=data[1:,:]#eliminate first row of data (row 0)
t=data[:,0]#t is the first column (column 0)
y=data[:,1]#y is the second column (column 1)
Matlab users can use:
[t,y]=textread('fourier_hw1.txt','%f%f','headerlines',1);
Be careful about how the data is read in. Are the column labels ignored or do they create false 0,0 data points? Check the first few rows of the data. This will mess up the fft.
System Modeling/Identification Homework
bodeplot.m (0.535 Kb)ltisys.py (17.163 Kb)
System 1 - step response (16.404 Kb)
System 2 - step response (22.048 Kb)
System 1 - swept sine response (36.924 Kb)
System 2 - swept sine response (37.132 Kb)
Plot the step responses and swept sine responses vs. time from the data files. Find the transfer function for each system by taking the fft of the sweptsine data (generate Bode plots). Taking the step response and Bode plot together for each system, estimate the parameters for each system (come up with a transfer function model with known coefficients).
Verify your transfer functions by overlaying Bode plots from your model and the data.
Be sure to clearly label your plots and submit your code.
Due Friday 9/22
Python users must replace the file ltisys.py in the folder:
C:\Python24\Lib\site-packages\scipy\signal
with the one above to run simulations (otherwise you will get an error message).
Lowpass Filter Homework
lowpass_homework.pdf (40.627 Kb)Due Friday, Sept. 1