49 lines
1.3 KiB
Matlab
49 lines
1.3 KiB
Matlab
%% Clear Workspace and Close figures
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clear; close all; clc;
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%% Intialize Laplace variable
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s = zpk('s');
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% Load data
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% We load the data of the z axis of two geophones.
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meas_sr = load('mat/data_018.mat', 'data'); meas_sr = meas_sr.data;
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meas_di = load('mat/data_019.mat', 'data'); meas_di = meas_di.data;
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% Analysis - Time Domain
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% First, we compare the time domain signals for the two experiments (figure [[fig:slipring_time]]).
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figure;
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hold on;
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plot(meas_di(:, 3), meas_di(:, 2), 'DisplayName', 'Geophone - Direct');
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plot(meas_sr(:, 3), meas_sr(:, 2), 'DisplayName', 'Geophone - Slip-Ring');
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hold off;
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xlabel('Time [s]'); ylabel('Voltage [V]');
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xlim([0, 50]);
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legend('location', 'northeast');
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% Analysis - Frequency Domain
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% We then compute the Power Spectral Density of the two signals and we compare them (figure [[fig:slipring_asd]]).
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dt = meas_di(2, 3) - meas_di(1, 3);
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Fs = 1/dt;
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win = hanning(ceil(5*Fs));
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[px_di, f] = pwelch(meas_di(:, 2), win, [], [], Fs);
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[px_sr, ~] = pwelch(meas_sr(:, 2), win, [], [], Fs);
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figure;
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hold on;
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plot(f, sqrt(px_sr), 'DisplayName', 'Slip-Ring');
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plot(f, sqrt(px_di), 'DisplayName', 'Wire');
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hold off;
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set(gca, 'xscale', 'log');
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set(gca, 'yscale', 'log');
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xlabel('Frequency [Hz]'); ylabel('Amplitude Spectral Density $\left[\frac{V}{\sqrt{Hz}}\right]$')
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xlim([1, 500]);
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legend('Location', 'southwest');
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