Fix DK iteration scales, add realistic values

also separate performance requirements from hinf and musyn

1 files changed, 34 insertions, 4 deletions

diff --git a/uav_uncertainty.m b/uav_uncertainty.m
index e1ddf76..6f28d8d 100644
--- a/uav_uncertainty.m
+++ b/uav_uncertainty.m
@@ -13,16 +13,46 @@
 %   UNCERT  Struct of uncertainty transfer functions
 
 
-function [uncert] = uav_performance(params, plot)
+function [uncert] = uav_performance(params, do_plots)
 
-W_malpha = tf(1,1);
-W_momega = tf(1,1);
-W_mState = tf(1,1);
+s = tf('s');
+
+% relative errors
+eps_T = params.aerodynamics.ThrustOmegaPropUncertainty;
+eps_r = params.mechanical.GyroscopicInertiaZUncertainty;
+eps_S = params.aerodynamics.FlapAreaUncertainty;
+eps_l = params.aerodynamics.LiftCoefficientUncertainty;
+eps_d = params.aerodynamics.DragCoefficientsUncertainties(1);
+% eps_0 = params.aerodynamics.DragCoefficients(2);
+
+eps_omega = max(.5 * eps_T, eps_r);
+eps_alpha = max(eps_l + eps_S + 2 * eps_omega, eps_S + eps_d + eps_omega);
+
+% band pass parameters for W_malpha
+wh = 20; % high freq
+wl = .1; % low freq
+
+W_malpha = eps_alpha * (s / wl) / ((s / wh + 1) * (s / wl + 1));
+W_momega = eps_omega * 10 / (s + 10);
+W_mState = .01 * 10 / (s + 10);
 
 uncert = struct(...
   'FlapAngle', W_malpha * eye(4), ...
   'Thrust', W_momega, ...
   'StateLinApprox', W_mState * eye(12));
 
+if do_plots
+  % Bode plots of performance requirements
+  figure; hold on;
+  bodemag(W_malpha);
+  bodemag(W_momega);
+  bodemag(W_mState);
+
+  grid on;
+  legend('$W_{m,\alpha}$', '$W_{m,\omega}$', '$W_{m,\mathbf{P}}$', ...
+    'interpreter', 'latex')
+  title('Stability (Uncertainty) Requirement')
+end
+
 end
 % vim: ts=2 sw=2 et: