96 lines
2.3 KiB
Matlab
96 lines
2.3 KiB
Matlab
%% Clear Workspace and Close figures
|
|
clear; close all; clc;
|
|
|
|
%% Intialize Laplace variable
|
|
s = zpk('s');
|
|
|
|
addpath('./mat/');
|
|
|
|
% Load Data :ignore:
|
|
% The data are loaded:
|
|
|
|
load('apa95ml_5kg_2a_1s.mat', 't', 'u', 'v');
|
|
|
|
|
|
|
|
% Any offset is removed.
|
|
|
|
u = detrend(u, 0); % Speedgoat DAC output Voltage [V]
|
|
v = detrend(v, 0); % Speedgoat ADC input Voltage (sensor stack) [V]
|
|
|
|
|
|
|
|
% Here, the amplifier gain is 20.
|
|
|
|
u = 20*u; % Actuator Stack Voltage [V]
|
|
|
|
% Compute TF estimate and Coherence :ignore:
|
|
% The transfer function from the actuator voltage $V_a$ to the force sensor stack voltage $V_s$ is computed.
|
|
|
|
|
|
Ts = t(end)/(length(t)-1);
|
|
Fs = 1/Ts;
|
|
|
|
win = hann(ceil(5/Ts));
|
|
|
|
[tf_est, f] = tfestimate(u, v, win, [], [], 1/Ts);
|
|
[coh, ~] = mscohere( u, v, win, [], [], 1/Ts);
|
|
|
|
|
|
|
|
% The coherence is shown in Figure [[fig:apa95ml_5kg_cedrat_coh]].
|
|
|
|
|
|
figure;
|
|
|
|
hold on;
|
|
plot(f, coh, 'k-')
|
|
set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin');
|
|
ylabel('Coherence'); xlabel('Frequency [Hz]');
|
|
hold off;
|
|
xlim([10, 5e3]);
|
|
|
|
|
|
|
|
% #+name: fig:apa95ml_5kg_cedrat_coh
|
|
% #+caption: Coherence
|
|
% #+RESULTS:
|
|
% [[file:figs/apa95ml_5kg_cedrat_coh.png]]
|
|
|
|
% The Simscape model is loaded and compared with the identified dynamics in Figure [[fig:bode_plot_force_sensor_voltage_comp_fem]].
|
|
% The non-minimum phase zero is just a side effect of the not so great identification.
|
|
% Taking longer measurements would results in a minimum phase zero.
|
|
|
|
|
|
load('mat/fem_simscape_models.mat', 'Gfm');
|
|
|
|
freqs = logspace(1, 4, 1000);
|
|
|
|
figure;
|
|
tiledlayout(3, 1, 'TileSpacing', 'None', 'Padding', 'None');
|
|
|
|
ax1 = nexttile([2,1]);
|
|
hold on;
|
|
plot(f, abs(tf_est))
|
|
plot(freqs, abs(squeeze(freqresp(Gfm, freqs, 'Hz'))))
|
|
set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'log');
|
|
ylabel('Amplitude [V/V]'); set(gca, 'XTickLabel',[]);
|
|
hold off;
|
|
ylim([1e-3, 1e1]);
|
|
|
|
ax2 = nexttile;
|
|
hold on;
|
|
plot(f, 180/pi*angle(tf_est), ...
|
|
'DisplayName', 'Identification')
|
|
plot(freqs, 180/pi*angle(squeeze(freqresp(Gfm, freqs, 'Hz'))), ...
|
|
'DisplayName', 'FEM')
|
|
set(gca, 'Xscale', 'log'); set(gca, 'Yscale', 'lin');
|
|
ylabel('Phase'); xlabel('Frequency [Hz]');
|
|
hold off;
|
|
ylim([-180, 180]);
|
|
yticks(-180:90:180);
|
|
legend('location', 'northeast')
|
|
|
|
linkaxes([ax1,ax2], 'x');
|
|
xlim([10, 5e3]);
|