Add analysis about jacobian position
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figs/gravimeter_cl_transmissibility_coupling.pdf
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figs/gravimeter_cl_transmissibility_coupling.png
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figs/gravimeter_model_K.png
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figs/gravimeter_model_KM.png
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figs/gravimeter_model_M.png
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figs/gravimeter_rga_num.pdf
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figs/gravimeter_rga_num.png
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figs/gravimeter_transmissibility_offset_act.pdf
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figs/gravimeter_transmissibility_offset_act.png
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figs/jac_decoupling_K.pdf
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figs/jac_decoupling_K.png
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figs/jac_decoupling_KM.pdf
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figs/jac_decoupling_KM.png
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figs/jac_decoupling_M.pdf
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figs/jac_decoupling_M.png
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figs/leg_model.png
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index.html
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index.org
@ -96,6 +96,10 @@ The model of the gravimeter is schematically shown in Figure [[fig:gravimeter_mo
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#+caption: Model of the gravimeter
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[[file:figs/gravimeter_model.png]]
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#+name: fig:leg_model
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#+caption: Model of the struts
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[[file:figs/leg_model.png]]
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The parameters used for the simulation are the following:
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#+begin_src matlab
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l = 1.0; % Length of the mass [m]
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@ -267,14 +271,14 @@ $\bm{G}_x(s)$ correspond to the $3 \times 3$transfer function matrix from forces
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The Jacobian corresponding to the sensors and actuators are defined below:
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#+begin_src matlab
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Ja = [1 0 h/2
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0 1 -l/2
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1 0 -h/2
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Ja = [1 0 -h/2
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0 1 l/2
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1 0 h/2
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0 1 0];
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Jt = [1 0 ha
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0 1 -la
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0 1 la];
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Jt = [1 0 -ha
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0 1 la
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0 1 -la];
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#+end_src
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And the plant $\bm{G}_x$ is computed:
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@ -364,6 +368,27 @@ Now, the Singular Value Decomposition of $H_1$ is performed:
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[U,S,V] = svd(H1);
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#+end_src
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#+begin_src matlab :exports results :results value table replace :tangle no
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data2orgtable(U, {}, {}, ' %.2f ');
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#+end_src
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#+caption: $U$ matrix
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#+RESULTS:
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| -0.78 | 0.26 | -0.53 | -0.2 |
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| 0.4 | 0.61 | -0.04 | -0.68 |
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| 0.48 | -0.14 | -0.85 | 0.2 |
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| 0.03 | 0.73 | 0.06 | 0.68 |
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#+begin_src matlab :exports results :results value table replace :tangle no
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data2orgtable(V, {}, {}, ' %.2f ');
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#+end_src
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#+caption: $V$ matrix
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#+RESULTS:
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| -0.79 | 0.11 | -0.6 |
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| 0.51 | 0.67 | -0.54 |
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| -0.35 | 0.73 | 0.59 |
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The obtained matrices $U$ and $V$ are used to decouple the system as shown in Figure [[fig:gravimeter_decouple_svd]].
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#+begin_src latex :file gravimeter_decouple_svd.pdf :tangle no :exports results
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@ -594,6 +619,48 @@ The obtained RGA elements are shown in Figure [[fig:gravimeter_rga]].
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#+RESULTS:
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[[file:figs/gravimeter_rga.png]]
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The RGA-number is also a measure of diagonal dominance:
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\begin{equation}
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\text{RGA-number} = \| \Lambda(G) - I \|_\text{sum}
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\end{equation}
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#+begin_src matlab :exports none
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% Relative Gain Array for the decoupled plant using SVD:
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RGA_svd = zeros(size(Gsvd,1), size(Gsvd,2), length(freqs));
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Gsvd_inv = inv(Gsvd);
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for f_i = 1:length(freqs)
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RGA_svd(:, :, f_i) = abs(evalfr(Gsvd, j*2*pi*freqs(f_i)).*evalfr(Gsvd_inv, j*2*pi*freqs(f_i))');
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end
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% Relative Gain Array for the decoupled plant using the Jacobian:
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RGA_x = zeros(size(Gx,1), size(Gx,2), length(freqs));
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Gx_inv = inv(Gx);
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for f_i = 1:length(freqs)
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RGA_x(:, :, f_i) = abs(evalfr(Gx, j*2*pi*freqs(f_i)).*evalfr(Gx_inv, j*2*pi*freqs(f_i))');
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end
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#+end_src
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#+begin_src matlab :exports none
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RGA_num_svd = squeeze(sum(sum(RGA_svd - eye(3))));
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RGA_num_x = squeeze(sum(sum(RGA_x - eye(3))));
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figure;
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hold on;
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plot(freqs, RGA_num_svd)
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plot(freqs, RGA_num_x)
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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xlabel('Frequency [Hz]'); ylabel('RGA-Number');
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#+end_src
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#+begin_src matlab :tangle no :exports results :results file replace
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exportFig('figs/gravimeter_rga_num.pdf', 'width', 'wide', 'height', 'normal');
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#+end_src
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#+name: fig:gravimeter_rga_num
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#+caption: RGA-Number for the Gravimeter
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#+RESULTS:
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[[file:figs/gravimeter_rga_num.png]]
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** Obtained Decoupled Plants
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<<sec:gravimeter_decoupled_plant>>
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@ -920,6 +987,555 @@ The obtained transmissibility in Open-loop, for the centralized control as well
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#+RESULTS:
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[[file:figs/gravimeter_platform_simscape_cl_transmissibility.png]]
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#+begin_src matlab :exports results
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freqs = logspace(-2, 2, 1000);
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figure;
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hold on;
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for out_i = 1:3
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for in_i = out_i+1:3
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set(gca,'ColorOrderIndex',1)
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plot(freqs, abs(squeeze(freqresp(G( out_i,in_i), freqs, 'Hz'))));
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set(gca,'ColorOrderIndex',2)
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plot(freqs, abs(squeeze(freqresp(G_cen(out_i,in_i), freqs, 'Hz'))));
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set(gca,'ColorOrderIndex',3)
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plot(freqs, abs(squeeze(freqresp(G_svd(out_i,in_i), freqs, 'Hz'))), '--');
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end
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end
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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ylabel('Transmissibility'); xlabel('Frequency [Hz]');
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#+end_src
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#+begin_src matlab :tangle no :exports results :results file replace
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exportFig('figs/gravimeter_cl_transmissibility_coupling.pdf', 'width', 'wide', 'height', 'normal');
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#+end_src
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#+name: fig:gravimeter_cl_transmissibility_coupling
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#+caption: Obtain coupling terms of the transmissibility matrix
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#+RESULTS:
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[[file:figs/gravimeter_cl_transmissibility_coupling.png]]
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** Robustness to a change of actuator position
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Let say we change the position of the actuators:
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#+begin_src matlab
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la = l/2*0.7; % Position of Act. [m]
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ha = h/2*0.7; % Position of Act. [m]
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#+end_src
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#+begin_src matlab :exports none
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%% Name of the Simulink File
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mdl = 'gravimeter';
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%% Input/Output definition
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clear io; io_i = 1;
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io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
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G = linearize(mdl, io);
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G.InputName = {'F1', 'F2', 'F3'};
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G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
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#+end_src
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#+begin_src matlab :exports none
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G_cen_b = feedback(G, pinv(Jt')*K_cen*pinv(Ja));
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G_svd_b = feedback(G, inv(V')*K_svd*U_inv(1:3, :));
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#+end_src
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The new plant is computed, and the centralized and SVD control architectures are applied using the previsouly computed Jacobian matrices and $U$ and $V$ matrices.
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The closed-loop system are still stable, and their
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#+begin_src matlab :exports results
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freqs = logspace(-2, 2, 1000);
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figure;
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tiledlayout(1, 3, 'TileSpacing', 'None', 'Padding', 'None');
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ax1 = nexttile;
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hold on;
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plot(freqs, abs(squeeze(freqresp(G_cen(1,1)/s^2, freqs, 'Hz'))), 'DisplayName', 'Initial');
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plot(freqs, abs(squeeze(freqresp(G_cen_b(1,1)/s^2, freqs, 'Hz'))), 'DisplayName', 'Jacobian');
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plot(freqs, abs(squeeze(freqresp(G_svd_b(1,1)/s^2, freqs, 'Hz'))), '--', 'DisplayName', 'SVD');
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hold off;
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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ylabel('Transmissibility'); xlabel('Frequency [Hz]');
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title('$D_x/D_{w,x}$');
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legend('location', 'southwest');
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ax2 = nexttile;
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hold on;
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plot(freqs, abs(squeeze(freqresp(G_cen(2,2)/s^2, freqs, 'Hz'))));
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plot(freqs, abs(squeeze(freqresp(G_cen_b(2,2)/s^2, freqs, 'Hz'))));
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plot(freqs, abs(squeeze(freqresp(G_svd_b(2,2)/s^2, freqs, 'Hz'))), '--');
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hold off;
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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set(gca, 'YTickLabel',[]); xlabel('Frequency [Hz]');
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title('$D_z/D_{w,z}$');
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ax3 = nexttile;
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hold on;
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plot(freqs, abs(squeeze(freqresp(G_cen(3,3)/s^2, freqs, 'Hz'))));
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plot(freqs, abs(squeeze(freqresp(G_cen_b(3,3)/s^2, freqs, 'Hz'))));
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plot(freqs, abs(squeeze(freqresp(G_svd_b(3,3)/s^2, freqs, 'Hz'))), '--');
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hold off;
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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set(gca, 'YTickLabel',[]); xlabel('Frequency [Hz]');
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title('$R_y/R_{w,y}$');
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linkaxes([ax1,ax2,ax3],'xy');
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xlim([freqs(1), freqs(end)]);
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xlim([1e-2, 5e1]); ylim([1e-7, 3e-4]);
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#+end_src
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#+begin_src matlab :tangle no :exports results :results file replace
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exportFig('figs/gravimeter_transmissibility_offset_act.pdf', 'width', 'wide', 'height', 'normal');
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#+end_src
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#+name: fig:gravimeter_transmissibility_offset_act
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#+caption: Transmissibility for the initial CL system and when the position of actuators are changed
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#+RESULTS:
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[[file:figs/gravimeter_transmissibility_offset_act.png]]
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** Combined / comparison of K and M decoupling
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*** Introduction :ignore:
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If we want to decouple the system at low frequency (determined by the stiffness matrix), we have to compute the Jacobians at a point where the stiffness matrix is diagonal.
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A displacement (resp. rotation) of the mass at this particular point should induce a *pure* force (resp. torque) on the same point due to stiffnesses in the system.
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This can be verified by geometrical computations.
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If we want to decouple the system at high frequency (determined by the mass matrix), we have tot compute the Jacobians at the Center of Mass of the suspended solid.
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Similarly to the stiffness analysis, when considering only the inertia effects (neglecting the stiffnesses), a force (resp. torque) applied at this point (the center of mass) should induce a *pure* acceleration (resp. angular acceleration).
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Ideally, we would like to have a decoupled mass matrix and stiffness matrix at the same time.
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To do so, the actuators (springs) should be positioned such that the stiffness matrix is diagonal when evaluated at the CoM of the solid.
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*** Decoupling of the mass matrix
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#+name: fig:gravimeter_model_M
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#+caption: Choice of {O} such that the Mass Matrix is Diagonal
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[[file:figs/gravimeter_model_M.png]]
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#+begin_src matlab
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la = l/2; % Position of Act. [m]
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ha = h/2; % Position of Act. [m]
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#+end_src
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#+begin_src matlab
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%% Name of the Simulink File
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mdl = 'gravimeter';
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%% Input/Output definition
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clear io; io_i = 1;
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io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
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io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
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G = linearize(mdl, io);
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G.InputName = {'F1', 'F2', 'F3'};
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G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
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#+end_src
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Decoupling at the CoM (Mass decoupled)
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#+begin_src matlab
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JMa = [1 0 -h/2
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0 1 l/2
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1 0 h/2
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0 1 0];
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JMt = [1 0 -ha
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0 1 la
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0 1 -la];
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#+end_src
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#+begin_src matlab
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GM = pinv(JMa)*G*pinv(JMt');
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GM.InputName = {'Fx', 'Fz', 'My'};
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GM.OutputName = {'Dx', 'Dz', 'Ry'};
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#+end_src
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#+begin_src matlab :exports none
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figure;
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% Magnitude
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hold on;
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for i_in = 1:3
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for i_out = [1:i_in-1, i_in+1:3]
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plot(freqs, abs(squeeze(freqresp(GM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
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'HandleVisibility', 'off');
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||||
end
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end
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plot(freqs, abs(squeeze(freqresp(GM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
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'DisplayName', '$G_x(i,j)\ i \neq j$');
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set(gca,'ColorOrderIndex',1)
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for i_in_out = 1:3
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plot(freqs, abs(squeeze(freqresp(GM(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
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||||
end
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hold off;
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set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
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||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
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||||
legend('location', 'southeast');
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ylim([1e-8, 1e0]);
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||||
#+end_src
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||||
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||||
#+begin_src matlab :tangle no :exports results :results file replace
|
||||
exportFig('figs/jac_decoupling_M.pdf', 'width', 'wide', 'height', 'normal');
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||||
#+end_src
|
||||
|
||||
#+name: fig:jac_decoupling_M
|
||||
#+caption:
|
||||
#+RESULTS:
|
||||
[[file:figs/jac_decoupling_M.png]]
|
||||
|
||||
*** Decoupling of the stiffness matrix
|
||||
|
||||
#+name: fig:gravimeter_model_K
|
||||
#+caption: Choice of {O} such that the Stiffness Matrix is Diagonal
|
||||
[[file:figs/gravimeter_model_K.png]]
|
||||
|
||||
Decoupling at the point where K is diagonal (x = 0, y = -h/2 from the schematic {O} frame):
|
||||
#+begin_src matlab
|
||||
JKa = [1 0 0
|
||||
0 1 -l/2
|
||||
1 0 -h
|
||||
0 1 0];
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||||
|
||||
JKt = [1 0 0
|
||||
0 1 -la
|
||||
0 1 la];
|
||||
#+end_src
|
||||
|
||||
And the plant $\bm{G}_x$ is computed:
|
||||
#+begin_src matlab
|
||||
GK = pinv(JKa)*G*pinv(JKt');
|
||||
GK.InputName = {'Fx', 'Fz', 'My'};
|
||||
GK.OutputName = {'Dx', 'Dz', 'Ry'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :exports none
|
||||
figure;
|
||||
|
||||
% Magnitude
|
||||
hold on;
|
||||
for i_in = 1:3
|
||||
for i_out = [1:i_in-1, i_in+1:3]
|
||||
plot(freqs, abs(squeeze(freqresp(GK(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'HandleVisibility', 'off');
|
||||
end
|
||||
end
|
||||
plot(freqs, abs(squeeze(freqresp(GK(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'DisplayName', '$G_x(i,j)\ i \neq j$');
|
||||
set(gca,'ColorOrderIndex',1)
|
||||
for i_in_out = 1:3
|
||||
plot(freqs, abs(squeeze(freqresp(GK(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
|
||||
end
|
||||
hold off;
|
||||
set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
|
||||
legend('location', 'southeast');
|
||||
ylim([1e-8, 1e0]);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :tangle no :exports results :results file replace
|
||||
exportFig('figs/jac_decoupling_K.pdf', 'width', 'wide', 'height', 'normal');
|
||||
#+end_src
|
||||
|
||||
#+name: fig:jac_decoupling_K
|
||||
#+caption:
|
||||
#+RESULTS:
|
||||
[[file:figs/jac_decoupling_K.png]]
|
||||
|
||||
*** Combined decoupling of the mass and stiffness matrices
|
||||
|
||||
#+name: fig:gravimeter_model_KM
|
||||
#+caption: Ideal location of the actuators such that both the mass and stiffness matrices are diagonal
|
||||
[[file:figs/gravimeter_model_KM.png]]
|
||||
|
||||
To do so, the actuator position should be modified
|
||||
|
||||
#+begin_src matlab
|
||||
la = l/2; % Position of Act. [m]
|
||||
ha = 0; % Position of Act. [m]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
%% Name of the Simulink File
|
||||
mdl = 'gravimeter';
|
||||
|
||||
%% Input/Output definition
|
||||
clear io; io_i = 1;
|
||||
io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
|
||||
G = linearize(mdl, io);
|
||||
G.InputName = {'F1', 'F2', 'F3'};
|
||||
G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
JMa = [1 0 -h/2
|
||||
0 1 l/2
|
||||
1 0 h/2
|
||||
0 1 0];
|
||||
|
||||
JMt = [1 0 -ha
|
||||
0 1 la
|
||||
0 1 -la];
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
GKM = pinv(JMa)*G*pinv(JMt');
|
||||
GKM.InputName = {'Fx', 'Fz', 'My'};
|
||||
GKM.OutputName = {'Dx', 'Dz', 'Ry'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :exports none
|
||||
figure;
|
||||
|
||||
% Magnitude
|
||||
hold on;
|
||||
for i_in = 1:3
|
||||
for i_out = [1:i_in-1, i_in+1:3]
|
||||
plot(freqs, abs(squeeze(freqresp(GKM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'HandleVisibility', 'off');
|
||||
end
|
||||
end
|
||||
plot(freqs, abs(squeeze(freqresp(GKM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'DisplayName', '$G_x(i,j)\ i \neq j$');
|
||||
set(gca,'ColorOrderIndex',1)
|
||||
for i_in_out = 1:3
|
||||
plot(freqs, abs(squeeze(freqresp(GKM(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
|
||||
end
|
||||
hold off;
|
||||
set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
|
||||
legend('location', 'southeast');
|
||||
ylim([1e-8, 1e0]);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :tangle no :exports results :results file replace
|
||||
exportFig('figs/jac_decoupling_KM.pdf', 'width', 'wide', 'height', 'normal');
|
||||
#+end_src
|
||||
|
||||
#+name: fig:jac_decoupling_KM
|
||||
#+caption:
|
||||
#+RESULTS:
|
||||
[[file:figs/jac_decoupling_KM.png]]
|
||||
|
||||
*** Conclusion
|
||||
|
||||
Ideally, the mechanical system should be designed in order to have a decoupled stiffness matrix at the CoM of the solid.
|
||||
|
||||
If not the case, the system can either be decoupled as low frequency if the Jacobian are evaluated at a point where the stiffness matrix is decoupled.
|
||||
Or it can be decoupled at high frequency if the Jacobians are evaluated at the CoM.
|
||||
|
||||
** SVD decoupling performances :noexport:
|
||||
|
||||
#+begin_src matlab
|
||||
la = l/2; % Position of Act. [m]
|
||||
ha = 0; % Position of Act. [m]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
c = 2e1; % Actuator Damping [N/(m/s)]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
%% Name of the Simulink File
|
||||
mdl = 'gravimeter';
|
||||
|
||||
%% Input/Output definition
|
||||
clear io; io_i = 1;
|
||||
io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
|
||||
G = linearize(mdl, io);
|
||||
G.InputName = {'F1', 'F2', 'F3'};
|
||||
G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
wc = 2*pi*10; % Decoupling frequency [rad/s]
|
||||
H1 = evalfr(G, j*wc);
|
||||
D = pinv(real(H1'*H1));
|
||||
H1 = pinv(D*real(H1'*diag(exp(j*angle(diag(H1*D*H1.'))/2))));
|
||||
[U,S,V] = svd(H1);
|
||||
Gsvd = inv(U)*G*inv(V');
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
c = 5e2; % Actuator Damping [N/(m/s)]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
%% Name of the Simulink File
|
||||
mdl = 'gravimeter';
|
||||
|
||||
%% Input/Output definition
|
||||
clear io; io_i = 1;
|
||||
io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
|
||||
G = linearize(mdl, io);
|
||||
G.InputName = {'F1', 'F2', 'F3'};
|
||||
G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
wc = 2*pi*10; % Decoupling frequency [rad/s]
|
||||
H1 = evalfr(G, j*wc);
|
||||
D = pinv(real(H1'*H1));
|
||||
H1 = pinv(D*real(H1'*diag(exp(j*angle(diag(H1*D*H1.'))/2))));
|
||||
[U,S,V] = svd(H1);
|
||||
Gsvdd = inv(U)*G*inv(V');
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
JMa = [1 0 -h/2
|
||||
0 1 l/2
|
||||
1 0 h/2
|
||||
0 1 0];
|
||||
|
||||
JMt = [1 0 -ha
|
||||
0 1 la
|
||||
0 1 -la];
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
GM = pinv(JMa)*G*pinv(JMt');
|
||||
GM.InputName = {'Fx', 'Fz', 'My'};
|
||||
GM.OutputName = {'Dx', 'Dz', 'Ry'};
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :exports none
|
||||
figure;
|
||||
|
||||
% Magnitude
|
||||
hold on;
|
||||
for i_in = 1:3
|
||||
for i_out = [1:i_in-1, i_in+1:3]
|
||||
plot(freqs, abs(squeeze(freqresp(GM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'HandleVisibility', 'off');
|
||||
end
|
||||
end
|
||||
plot(freqs, abs(squeeze(freqresp(GM(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'DisplayName', '$G_x(i,j)\ i \neq j$');
|
||||
set(gca,'ColorOrderIndex',1)
|
||||
for i_in_out = 1:3
|
||||
plot(freqs, abs(squeeze(freqresp(GM(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
|
||||
end
|
||||
hold off;
|
||||
set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
|
||||
legend('location', 'southeast');
|
||||
ylim([1e-8, 1e0]);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :exports none
|
||||
figure;
|
||||
|
||||
% Magnitude
|
||||
hold on;
|
||||
for i_in = 1:3
|
||||
for i_out = [1:i_in-1, i_in+1:3]
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvd(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'HandleVisibility', 'off');
|
||||
end
|
||||
end
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvd(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'DisplayName', '$G_x(i,j)\ i \neq j$');
|
||||
set(gca,'ColorOrderIndex',1)
|
||||
for i_in_out = 1:3
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvd(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
|
||||
end
|
||||
hold off;
|
||||
set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
|
||||
legend('location', 'southeast');
|
||||
ylim([1e-8, 1e0]);
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab :exports none
|
||||
figure;
|
||||
|
||||
% Magnitude
|
||||
hold on;
|
||||
for i_in = 1:3
|
||||
for i_out = [1:i_in-1, i_in+1:3]
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvdd(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'HandleVisibility', 'off');
|
||||
end
|
||||
end
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvdd(i_out, i_in), freqs, 'Hz'))), 'color', [0,0,0,0.2], ...
|
||||
'DisplayName', '$G_x(i,j)\ i \neq j$');
|
||||
set(gca,'ColorOrderIndex',1)
|
||||
for i_in_out = 1:3
|
||||
plot(freqs, abs(squeeze(freqresp(Gsvdd(i_in_out, i_in_out), freqs, 'Hz'))), 'DisplayName', sprintf('$G_x(%d,%d)$', i_in_out, i_in_out));
|
||||
end
|
||||
hold off;
|
||||
set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log');
|
||||
xlabel('Frequency [Hz]'); ylabel('Magnitude');
|
||||
legend('location', 'southeast');
|
||||
ylim([1e-8, 1e0]);
|
||||
#+end_src
|
||||
|
||||
** SVD U and V matrices :noexport:
|
||||
|
||||
#+begin_src matlab
|
||||
la = l/2; % Position of Act. [m]
|
||||
ha = 0; % Position of Act. [m]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
c = 2e1; % Actuator Damping [N/(m/s)]
|
||||
#+end_src
|
||||
|
||||
#+begin_src matlab
|
||||
%% Name of the Simulink File
|
||||
mdl = 'gravimeter';
|
||||
|
||||
%% Input/Output definition
|
||||
clear io; io_i = 1;
|
||||
io(io_i) = linio([mdl, '/F1'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F2'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/F3'], 1, 'openinput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_side'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 1, 'openoutput'); io_i = io_i + 1;
|
||||
io(io_i) = linio([mdl, '/Acc_top'], 2, 'openoutput'); io_i = io_i + 1;
|
||||
|
||||
G = linearize(mdl, io);
|
||||
G.InputName = {'F1', 'F2', 'F3'};
|
||||
G.OutputName = {'Ax1', 'Az1', 'Ax2', 'Az2'};
|
||||
#+end_src
|
||||
|
||||
* Stewart Platform - Simscape Model
|
||||
:PROPERTIES:
|
||||
:header-args:matlab+: :tangle stewart_platform/script.m
|
||||
|