huddle test + tfestimate

runtest.m

@@ -0,0 +1,77 @@
+tg = slrt;
+
+%%
+f = SimulinkRealTime.openFTP(tg);
+mget(f, 'apa95ml.dat', 'data');
+close(f);
+
+%% Convert the Data
+data = SimulinkRealTime.utils.getFileScopeData('data/apa95ml.dat').data;
+
+u = data(:, 1);
+y = data(:, 2);
+t = data(:, 3);
+
+save('mat/apa95ml_5kg_10V.mat', 'u', 't', 'y');
+
+%%
+figure;
+subplot(1,2,1);
+plot(t, u)
+subplot(1,2,2);
+plot(t, y)
+
+%%
+load('mat/apa95ml_5kg_10V.mat', 'u', 't', 'y');
+ht = load('mat/huddle_test.mat', 'u', 't', 'y');
+u = u - mean(u);
+y = y - mean(y);
+
+%%
+[pxx, f] = pwelch(y, win, [], [], 1/Ts);
+[pht, ~] = pwelch(ht.y, win, [], [], 1/Ts);
+
+figure;
+
+hold on;
+plot(f, pxx);
+plot(f, pht);
+hold off;
+set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'log');
+ylabel('PSD'); xlabel('Frequency [Hz]');
+
+%%
+run setup;
+
+win = hann(ceil(10.1/Ts));
+
+[tf_est, f] = tfestimate(u, y, win, [], [], 1/Ts);
+[co_est, ~] = mscohere(u, y, win, [], [], 1/Ts);
+
+%%
+figure;
+
+hold on;
+plot(f, co_est, 'k-')
+set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin');
+ylabel('Coherence'); xlabel('Frequency [Hz]');
+hold off;
+
+%%
+figure;
+ax1 = subplot(2, 1, 1);
+hold on;
+plot(f, abs(tf_est), 'k-', 'DisplayName', 'Identified')
+set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'log');
+ylabel('Amplitude'); xlabel('Frequency [Hz]');
+hold off;
+
+ax2 = subplot(2, 1, 2);
+hold on;
+plot(f, 180/pi*unwrap(angle(-tf_est)), 'k-')
+set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin');
+ylabel('Phase'); xlabel('Frequency [Hz]');
+hold off;
+
+linkaxes([ax1,ax2], 'x');
+xlim([10, 5000]);

setup.m

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+s = tf('s');
+Ts = 1e-4;
+
+Glpf = 1/(1 + s/2/pi/500);
+
+Gz = c2d(Glpf, Ts, 'tustin');