%% Clear Workspace and Close figures clear; close all; clc; %% Intialize Laplace variable s = zpk('s'); %% Path for functions, data and scripts addpath('./mat/'); % Path for data %% Colors for the figures colors = colororder; %% Uniaxial Simscape model name mdl = 'nass_uniaxial_model'; %% Frequency Vector [Hz] freqs = logspace(0, 3, 1000); % #+name: fig:micro_station_uniaxial_model % #+caption: Schematic of the Micro-Station measurement setup and uniaxial model. % #+begin_figure % #+attr_latex: :caption \subcaption{\label{fig:micro_station_meas_dynamics_schematic}Measurement setup - Schematic} % #+attr_latex: :options {0.69\textwidth} % #+begin_subfigure % #+attr_latex: :scale 1 % [[file:figs/micro_station_meas_dynamics_schematic.png]] % #+end_subfigure % #+attr_latex: :caption \subcaption{\label{fig:uniaxial_model_micro_station}Uniaxial model of the micro-station} % #+attr_latex: :options {0.29\textwidth} % #+begin_subfigure % #+attr_latex: :scale 1 % [[file:figs/uniaxial_model_micro_station.png]] % #+end_subfigure % #+end_figure % Due to the bad coherence at low frequency, the frequency response functions will only be shown between 20 and 200Hz (solid lines in Figure ref:fig:uniaxial_comp_frf_meas_model). %% Load measured FRF load('meas_microstation_frf.mat'); % Masses are estimated from the CAD. %% Parameters - Mass mh = 15; % Micro Hexapod [kg] mt = 1200; % Ty + Ry + Rz [kg] mg = 2500; % Granite [kg] % And stiffnesses from the data-sheet of stage manufacturers. %% Parameters - Stiffnesses kh = 6.11e+07; % [N/m] kt = 5.19e+08; % [N/m] kg = 9.50e+08; % [N/m] % The damping coefficients are tuned to match the identified damping from the measurements. %% Parameters - damping ch = 2*0.05*sqrt(kh*mh); % [N/(m/s)] ct = 2*0.05*sqrt(kt*mt); % [N/(m/s)] cg = 2*0.08*sqrt(kg*mg); % [N/(m/s)] %% Save model parameters save('./mat/uniaxial_micro_station_parameters.mat', 'mh', 'mt', 'mg', 'ch', 'ct', 'cg', 'kh', 'kt', 'kg') %% Disable the Nano-Hexpod for now model_config = struct(); model_config.nhexa = "none"; model_config.controller = "open_loop"; %% Identify the transfer function from u to taum clear io; io_i = 1; io(io_i) = linio([mdl, '/micro_station/Fg'], 1, 'openinput'); io_i = io_i + 1; % Hammer on Granite io(io_i) = linio([mdl, '/micro_station/Fh'], 1, 'openinput'); io_i = io_i + 1; % Hammer on Hexapod io(io_i) = linio([mdl, '/micro_station/xg'], 1, 'openoutput'); io_i = io_i + 1; % Absolute motion of Granite io(io_i) = linio([mdl, '/micro_station/xh'], 1, 'openoutput'); io_i = io_i + 1; % Absolute motion of Hexapod %% Perform the model extraction G_id = linearize(mdl, io, 0.0); G_id.InputName = {'Fg', 'Fh'}; G_id.OutputName = {'Dg', 'Dh'}; % Comparison of the model and measurements % The comparison between the measurements and the model is shown in Figure ref:fig:uniaxial_comp_frf_meas_model. % Only three modes are modelled with frequencies at 70Hz, 140Hz and 320Hz. % As the model is simplistic, the goal is not to match exactly the measurement but to have a first approximation. % More accurate models will be used later on. %% Comparison of the measured FRF and identified ones from the uni-axial model figure; tiledlayout(3, 1, 'TileSpacing', 'Compact', 'Padding', 'None'); ax1 = nexttile([2,1]); hold on; plot(f(f>20), abs(frf_Fhz_to_Dhz(f>20)), '-', 'color', colors(1,:), 'DisplayName', '$D_{h,z}/F_{h,z}$'); plot(f(f>20), abs(frf_Fgz_to_Dhz(f>20)), '-', 'color', colors(2,:), 'DisplayName', '$D_{h,z}/F_{g,z}$'); plot(f(f>20), abs(frf_Fgz_to_Dgz(f>20)), '-', 'color', colors(3,:), 'DisplayName', '$D_{g,z}/F_{g,z}$'); plot(freqs, abs(squeeze(freqresp(G_id('Dh', 'Fh'), freqs, 'Hz'))), '--', 'color', colors(1,:), 'DisplayName', '$D_{h,z}/F_{h,z}$ (model)'); plot(freqs, abs(squeeze(freqresp(G_id('Dh', 'Fg'), freqs, 'Hz'))), '--', 'color', colors(2,:), 'DisplayName', '$D_{h,z}/F_{g,z}$ (model)'); plot(freqs, abs(squeeze(freqresp(G_id('Dg', 'Fg'), freqs, 'Hz'))), '--', 'color', colors(3,:), 'DisplayName', '$D_{g,z}/F_{g,z}$ (model)'); hold off; set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log'); ylabel('Amplitude [m/N]'); set(gca, 'XTickLabel',[]); ylim([1e-10, 2e-7]); legend('location', 'northwest', 'FontSize', 8, 'NumColumns', 2); ax2 = nexttile; hold on; plot(freqs, 180/pi*unwrap(angle(squeeze(freqresp(G_id('Dh', 'Fh'), freqs, 'Hz')))), '--', 'color', colors(1,:)); plot(freqs, 180/pi*unwrap(angle(squeeze(freqresp(G_id('Dh', 'Fg'), freqs, 'Hz')))), '--', 'color', colors(2,:)); plot(freqs, 180/pi*unwrap(angle(squeeze(freqresp(G_id('Dg', 'Fg'), freqs, 'Hz')))), '--', 'color', colors(3,:)); plot(f(f>20), 180/pi*unwrap(angle(frf_Fhx_to_Dhx(f>20))), '-', 'color', colors(1,:)); plot(f(f>30), 180/pi*unwrap(angle(frf_Fgx_to_Dhx(f>30))), '-', 'color', colors(2,:)); plot(f(f>20), 180/pi*unwrap(angle(frf_Fgx_to_Dgx(f>20))), '-', 'color', colors(3,:)); hold off; set(gca, 'XScale', 'log'); set(gca, 'YScale', 'lin'); xlabel('Frequency [Hz]'); ylabel('Phase [deg]'); hold off; yticks(-360:90:360); ylim([-360, 90]); linkaxes([ax1,ax2],'x'); xlim([1, 500]);