first measurements

matlab/analysis.m

@@ -1,4 +1,64 @@
+%% Remove first second
+Ts = t(2)-t(1);
+t = t(ceil(1/Ts):end);
+d = d(ceil(1/Ts):end);
+dp = dp(ceil(1/Ts):end);
+F = F(ceil(1/Ts):end);
+
+t = t - t(1);
+F = F - F(1);
+
+%% LPf
+s = tf('s');
+G_lpf = 1/(1+s/2/pi/10);
+F = lsim(G_lpf, F, t);
+d = lsim(G_lpf, d, t);
+dp = lsim(G_lpf, dp, t);
+
+%%
 figure;
-plot(F, d);
+plot(t, F);
+
+figure;
+hold on;
+plot(t, d, 'DisplayName', 'Encoder');
+plot(t, dp, 'DisplayName', 'Mahr')
+hold off;
+legend;
+
+%%
+t_start = 0.05;
+t_end = 0.12;
+d = d(t < t_end & t > t_start);
+dp = dp(t < t_end & t > t_start);
+F = F(t < t_end & t > t_start);
+
+d = d - d(1);
+dp = dp - dp(1);
+F = F - F(1);
+
+%%
+figure;
+plot(F, dp);
 xlabel('Measured Force [N]');
-ylabel('Measured Displacement [um]');
+ylabel('Measured Displacement [m]');
+
+%%
+sprintf('Stiffness is %.3f [N/mm]', abs(1e-3*(d\F)))
+
+%%
+figure;
+hold on;
+plot(F, d);
+plot(F, F/(d\F));
+hold off;
+xlabel('Measured Force [N]');
+ylabel('Measured Displacement [m]');
+
+%%
+figure;
+hold on;
+plot(dp, d);
+hold off;
+xlabel('Probe [m]');
+ylabel('Encoder [m]');

matlab/run_test.m

@@ -10,7 +10,8 @@ data = SimulinkRealTime.utils.getFileScopeData('data/data.dat').data;
 
 d = data(:, 1);
 F = data(:, 2);
+dp = data(:, 3);
 t = data(:, end);
 
 %% Save
-save('mat/flex_1_x.mat', 't', 'd', 'F');
+save('mat/meas_stiff_probe.mat', 't', 'd', 'dp', 'F');

matlab/setup.m

@@ -2,5 +2,5 @@ Fs = 20e3; % [Hz]
 Ts = 1/Fs; % [s]
 
 %% Gains
-Gf = 10; % [N/V]
-Gd = 10e-6; % [m/V]
+Gf = 50/4; % [N/V]
+Gd = 1000e-6/3.333; % [m/V]