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Diffstat (limited to 'uav.m')
| -rw-r--r-- | uav.m | 107 |
1 files changed, 107 insertions, 0 deletions
@@ -0,0 +1,107 @@ +% Copyright (c) 2024, Naoki Sean Pross, ETH Zürich +% +% Controller design for a ducted fan VTOL micro-UAV. + +% ------------------------------------------------------------------------ +% Clear environment and generate parameters + +clear; clc; close all; s = tf('s'); +params = uav_params(); + +% ------------------------------------------------------------------------ +% Define performance requirements + +% Mechanically, flaps are constrained to a max of 20~25 degrees, +% and they have a maximal angular speed +alpha_max = params.actuators.ServoAbsMaxAngle; +alpha_dot_max = params.actuators.ServoNominalAngularVelocity; + +W_Palpha = (s + 100 * alpha_dot_max) / (s + alpha_dot_max); +W_Palpha = alpha_max * W_Palpha / dcgain(W_Palpha); % adjust gain + +% Mechanically we have a maximal angular velocity for the propeller in the +% thruster, also there are a lot of unmodelled dynamics in the thruster +omega_max = params.actuators.TurbineMaxSpeed; +W_Pomega = (s + 50 * omega_max) / (s + omega_max); + +% We want a nice and smooth movements +v_xy_max = params.performance.MaxHorizontalSpeed; +v_z_max = params.performance.MaxVerticalSpeed; + +W_Pxy = 1 / (s + 1 / v_xy_max); +W_Pz = 1 / (s + 1 / v_z_max); + +% Bode plots of performance requirements +figure; hold on; + +bodemag(1/W_Palpha); +bodemag(1/W_Pomega); +bodemag(1/W_Pxy); +bodemag(1/W_Pz); + +grid on; +legend('$W_{P,\alpha}$', '$W_{P,\omega}$', ... + '$W_{P,xy}$', '$W_{P,z}$', ... + 'interpreter', 'latex', 'fontSize', 8); +title('Performance requirements'); + +% Step response of position requirements +figure; hold on; +step(W_Pxy); step(W_Pz); +grid on; +legend('$W_{P,xy}$', '$W_{P,z}$', 'interpreter', 'latex', 'fontSize', 8); +title('Step responses of position performance requirements'); + +% Construct performance for position vector by combining xy and z +W_PP = blkdiag(W_Pxy * eye(2), W_Pz); + +perf = struct(... + 'FlapAngle', W_Palpha * eye(4), ... + 'Thrust', W_Pomega, ... + 'PositionAccuracy', W_PP); + +% ------------------------------------------------------------------------ +% Define stability requirements + +W_malpha = tf(1,1); +W_momega = tf(1,1); +W_mTheta = tf(1,1); +W_mOmega = tf(1,1); + +figure; hold on; + +bodemag(W_malpha); +bodemag(W_momega); +bodemag(W_mTheta); +bodemag(W_mOmega); + +grid on; +legend('$W_{m,\alpha}$', '$W_{m,\omega}$', ... + '$W_{m,\Theta}$', '$W_{m,\Omega}$', ... + 'interpreter', 'latex', 'fontSize', 8); +title('Uncertainties') + +uncert = struct(... + 'FlapAngle', W_malpha * eye(4), ... + 'Thrust', W_momega, ... + 'EulerAnglesApprox', W_mTheta * eye(3), ... + 'AngularRateApprox', W_mOmega * eye(3)); + +% ------------------------------------------------------------------------ +% Create UAV model + +model = uav_model(params, perf, uncert); + +% ------------------------------------------------------------------------ +% Perform H-infinity design + +Gnom = model.linear.StateSpace; +G = model.uncertain.StateSpace; + +% ------------------------------------------------------------------------ +% Verify performance satisfaction + +% ------------------------------------------------------------------------ +% Perform mu-Analysis & DK iteration + +% vim: ts=2 sw=2 et: |