%% Clear Workspace and Close figures clear; close all; clc; %% Intialize Laplace variable s = zpk('s'); addpath('flexor_025/'); open('flexor_025.slx'); % Import Mass Matrix, Stiffness Matrix, and Interface Nodes Coordinates % We first extract the stiffness and mass matrices. K = readmatrix('mat_K.CSV'); M = readmatrix('mat_M.CSV'); % #+caption: First 10x10 elements of the Mass matrix % #+RESULTS: % | 0.006 | 8e-09 | -2e-08 | -1e-10 | 3e-05 | 3e-08 | 0.003 | -3e-09 | 9e-09 | 2e-12 | % | 8e-09 | 0.02 | 1e-07 | -3e-05 | 1e-11 | 6e-10 | 1e-08 | 0.003 | -5e-08 | 3e-09 | % | -2e-08 | 1e-07 | 0.01 | -6e-08 | -6e-11 | -8e-12 | -1e-07 | 1e-08 | 0.003 | -1e-08 | % | -1e-10 | -3e-05 | -6e-08 | 1e-06 | 7e-14 | 6e-13 | 1e-10 | 1e-06 | -1e-08 | 3e-10 | % | 3e-05 | 1e-11 | -6e-11 | 7e-14 | 2e-07 | 1e-10 | 3e-08 | -7e-12 | 6e-11 | -6e-16 | % | 3e-08 | 6e-10 | -8e-12 | 6e-13 | 1e-10 | 5e-07 | 1e-08 | -5e-10 | -1e-11 | 1e-13 | % | 0.003 | 1e-08 | -1e-07 | 1e-10 | 3e-08 | 1e-08 | 0.02 | -2e-08 | 1e-07 | -4e-12 | % | -3e-09 | 0.003 | 1e-08 | 1e-06 | -7e-12 | -5e-10 | -2e-08 | 0.006 | -8e-08 | 3e-05 | % | 9e-09 | -5e-08 | 0.003 | -1e-08 | 6e-11 | -1e-11 | 1e-07 | -8e-08 | 0.01 | -6e-08 | % | 2e-12 | 3e-09 | -1e-08 | 3e-10 | -6e-16 | 1e-13 | -4e-12 | 3e-05 | -6e-08 | 2e-07 | % Then, we extract the coordinates of the interface nodes. [int_xyz, int_i, n_xyz, n_i, nodes] = extractNodes('out_nodes_3D.txt'); % Identification of the parameters using Simscape % The flexor is now imported into Simscape and its parameters are estimated using an identification. m = 1; % The dynamics is identified from the applied force/torque to the measured displacement/rotation of the flexor. %% Name of the Simulink File mdl = 'flexor_025'; %% Input/Output definition clear io; io_i = 1; io(io_i) = linio([mdl, '/T'], 1, 'openinput'); io_i = io_i + 1; io(io_i) = linio([mdl, '/D'], 1, 'openoutput'); io_i = io_i + 1; G = linearize(mdl, io); % Simpler Model % Let's now model the flexible joint with a "perfect" Bushing joint as shown in Figure [[fig:flexible_joint_simscape]]. % #+name: fig:flexible_joint_simscape % #+caption: Bushing Joint used to model the flexible joint % [[file:figs/flexible_joint_simscape.png]] % The parameters of the Bushing joint (stiffnesses) are estimated from the Stiffness matrix that was computed from the FEM. Kx = K(1,1); % [N/m] Ky = K(2,2); % [N/m] Kz = K(3,3); % [N/m] Krx = K(4,4); % [Nm/rad] Kry = K(5,5); % [Nm/rad] Krz = K(6,6); % [Nm/rad] % The dynamics from the applied force/torque to the measured displacement/rotation of the flexor is identified again for this simpler model. %% Name of the Simulink File mdl = 'flexor_025_simplified'; %% Input/Output definition clear io; io_i = 1; io(io_i) = linio([mdl, '/T'], 1, 'openinput'); io_i = io_i + 1; io(io_i) = linio([mdl, '/D'], 1, 'openoutput'); io_i = io_i + 1; Gs = linearize(mdl, io); % The two obtained dynamics are compared in Figure freqs = logspace(0, 5, 1000); figure; tiledlayout(1, 2, 'TileSpacing', 'None', 'Padding', 'None'); ax1 = nexttile; hold on; set(gca,'ColorOrderIndex',1) plot(freqs, abs(squeeze(freqresp(G(1,1), freqs, 'Hz'))), '-', 'DisplayName', '$D_x/F_x$'); set(gca,'ColorOrderIndex',1) plot(freqs, abs(squeeze(freqresp(Gs(1,1), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); set(gca,'ColorOrderIndex',2) plot(freqs, abs(squeeze(freqresp(G(2,2), freqs, 'Hz'))), '-', 'DisplayName', '$D_y/F_y$'); set(gca,'ColorOrderIndex',2) plot(freqs, abs(squeeze(freqresp(Gs(2,2), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); set(gca,'ColorOrderIndex',3) plot(freqs, abs(squeeze(freqresp(G(3,3), freqs, 'Hz'))), '-', 'DisplayName', '$D_z/F_z$'); set(gca,'ColorOrderIndex',3) plot(freqs, abs(squeeze(freqresp(Gs(3,3), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); hold off; set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log'); xlabel('Frequency [Hz]'); ylabel('Amplitude [m/N]'); hold off; legend('location', 'southwest'); ax2 = nexttile; hold on; set(gca,'ColorOrderIndex',1) plot(freqs, abs(squeeze(freqresp(G(4,4), freqs, 'Hz'))), '-', 'DisplayName', '$R_x/M_x$'); set(gca,'ColorOrderIndex',1) plot(freqs, abs(squeeze(freqresp(Gs(4,4), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); set(gca,'ColorOrderIndex',2) plot(freqs, abs(squeeze(freqresp(G(5,5), freqs, 'Hz'))), '-', 'DisplayName', '$R_y/M_y$'); set(gca,'ColorOrderIndex',2) plot(freqs, abs(squeeze(freqresp(Gs(5,5), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); set(gca,'ColorOrderIndex',3) plot(freqs, abs(squeeze(freqresp(G(6,6), freqs, 'Hz'))), '-', 'DisplayName', '$R_z/M_z$'); set(gca,'ColorOrderIndex',3) plot(freqs, abs(squeeze(freqresp(Gs(6,6), freqs, 'Hz'))), '--', 'HandleVisibility', 'off'); hold off; set(gca, 'XScale', 'log'); set(gca, 'YScale', 'log'); xlabel('Frequency [Hz]'); ylabel('Amplitude [rad/Nm]'); hold off; legend('location', 'southwest');