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-rw-r--r--uav.m219
1 files changed, 168 insertions, 51 deletions
diff --git a/uav.m b/uav.m
index 3a0da71..4810943 100644
--- a/uav.m
+++ b/uav.m
@@ -70,8 +70,8 @@ if do_hinf
hinfopt = hinfsynOptions('Display', 'off', 'Method', 'RIC', ...
'AutoScale', 'off', 'RelTol', 1e-3);
- [K_inf, ~, gamma, info] = hinfsyn(P_nom, nmeas, nctrl, hinfopt);
- fprintf(' - H-infinity synthesis gamma: %g\n', gamma);
+ [K_inf, ~, gamma_hinf, info] = hinfsyn(P_nom, nmeas, nctrl, hinfopt);
+ fprintf(' - H-infinity synthesis gamma: %g\n', gamma_hinf);
index = struct( ...
'Ix', 1, 'Iy', 2, 'Iz', 3, ...
@@ -88,7 +88,7 @@ if do_hinf
'index', index ...
);
- if gamma >= 1
+ if gamma_hinf >= 1
error('Failed to syntesize controller (closed loop is unstable).')
end
@@ -139,12 +139,11 @@ if do_hinf
writematrix([simout.Time', cols], 'fig/stepsim.dat', 'Delimiter', 'tab')
end
-
%% ------------------------------------------------------------------------
% Perform mu-Analysis & DK iteration
+drawnow;
if do_musyn
- drawnow;
fprintf('Performing mu-synthesis controller design...\n')
@@ -158,13 +157,13 @@ if do_musyn
% Options for H-infinity
nmeas = model.uncertain.Ny;
nctrl = model.uncertain.Nu;
- hinfopt = hinfsynOptions('Display', 'off', 'Method', 'RIC', ...
+ hinfopt = hinfsynOptions('Display', 'on', 'Method', 'RIC', ...
'AutoScale', 'on', 'RelTol', 1e-2);
% Frequency raster resolution to fit D scales
- nsamples = 300;
omega_max = 3;
- omega_min = -3;
+ omega_min = -2;
+ nsamples = (omega_max - omega_min) * 100;
omega = logspace(omega_min, omega_max, nsamples);
omega_range = {10^omega_min, 10^omega_max};
@@ -178,32 +177,68 @@ if do_musyn
fprintf(' - Will do (max) %d iterations.\n', niters);
% Maximum degree of D-scales and error
- d_scales_max_degree = 10;
- d_scales_max_err_p = .2; % in percentage
- d_scales_improvement_p = .1; % in percentage, avoid diminishing returns
+ d_scales_max_degree = 4;
+ d_scales_max_err = 15;
+ d_scales_max_err_p = .1; % in percentage
+ d_scales_improvement_p = .5; % in percentage, avoid diminishing returns
+
+ % Limit order of scaled plant
+ scaled_plant_reduce_ord = 100;
+ scaled_plant_reduce_maxerr = 1e-8;
+
+ % for plotting later
+ mu_plot_legend = {};
+
+ % For warm start
+ K_prev = {}; gamma_prev = {};
+ K_prev{1} = 0; gamma_prev{1} = inf;
+
+ mu_bounds_rp_prev = {}; mu_bounds_rs_prev = {};
+ D_left_prev = {}; D_right_prev = {};
+
+ % Start DK-iteration
+ warmit = 0;
+
+ % Do we have a lower bound for gamma?
+ gamma_max = 20;
+ gamma_min = .8;
+
+ %% Run D-K iteration
% hand tuned degrees, inf means will pick automatically best fit
% according to parameters given above
d_scales_degrees = {
- 0, 0, inf, inf, inf; % alpha
- 1, inf, inf, inf, inf; % omega
- 2, inf, inf, inf, inf; % state
- 0, 0, inf, inf, inf;
+ 0, 0, 0, inf, inf; % alpha
+ 0, inf, inf, inf, inf; % omega
+ 0, inf, inf, inf, inf; % state
+ 0, 0, 0, inf, inf; % perf
};
if size(d_scales_degrees, 2) < niters
- error('');
+ error('Number of columns of d_scales_degrees must match niter');
end
+
+ % if iterations fails set warmit and re-run this code section
+ if warmit > 0
+ fprintf("\n");
+ fprintf(" - Warm start, resuming from iteration %d.\n", warmit);
- scaled_plant_reduce_ord = 100;
- scaled_plant_reduce_maxerr = 1e-3;
+ K = K_prev{warmit};
+ gamma_max = gamma_prev{warmit};
+
+ mu_bounds_rp = mu_bounds_rp_prev{warmit};
+ mu_bounds_rs = mu_bounds_rs_prev{warmit};
- % for plotting later
- mu_plot_legend = {};
+ D_left = D_left_prev{warmit};
+ D_right = D_right_prev{warmit};
+
+ s = warmit;
+ else
+ s = 1;
+ end
- % Start DK-iteration
dkstart = tic;
- for it = 1:niters
+ for it = s:niters
fprintf(' * Running D-K iteration %d / %d...\n', it, niters);
itstart = tic();
@@ -216,7 +251,8 @@ if do_musyn
[P_scaled, ~] = prescale(P_scaled, omega_range);
n = size(P_scaled.A, 1);
- if n > scaled_plant_reduce_ord
+ % disabled
+ if false && n > scaled_plant_reduce_ord
R = reducespec(P_scaled, 'balanced'); % or ncf
R.Options.FreqIntervals = [omega_range{1}, omega_range{2}];
R.Options.Goal = 'absolute'; % better hinf norm
@@ -225,15 +261,76 @@ if do_musyn
view(R);
drawnow;
end
- P_scaled = getrom(R, MaxError=scaled_plant_reduce_maxerr);
+ P_scaled = getrom(R, MaxError=scaled_plant_reduce_maxerr, Method='truncate');
fprintf(' Scaled plant was reduced from order %d to %d\n', ...
n, size(P_scaled.A, 1))
end
+ % Check scaled plant meets H-infinity assumptions
+ A = P_scaled(idx.OutputUncertain, idx.InputUncertain);
+ Bu = P_scaled(idx.OutputUncertain, idx.InputNominal);
+ Cy = P_scaled(idx.OutputNominal, idx.InputUncertain);
+
+ [~, ~, ~, nustab, ~, nudetb] = pbhtest(A);
+ if nustab > 0 || nudetb > 0
+ fprintf(' Scaled plant has unstabilizable or undetectable A.\n');
+ end
+
+ [~, ~, ~, nustab, ~, nudetb] = pbhtest(Bu);
+ if nustab > 0 || nudetb > 0
+ fprintf(' Scaled plant has unstabilizable or undetectable Bu.\n');
+ end
+
+ [~, ~, ~, nustab, ~, nudetb] = pbhtest(Cy);
+ if nustab > 0 || nudetb > 0
+ fprintf(' Scaled plant has unstabilizable or undetectable Cy.\n');
+ end
+
+ Deu = P_scaled(idx.OutputError, idx.InputNominal);
+ Dyw = P_scaled(idx.OutputNominal, idx.InputExogenous);
+
+ if rank(ctrb(Deu)) < length(Deu.A) || rank(obsv(Deu)) < lenth(Deu.A)
+ fprintf(' Scaled plant has Deu that is not full rank.\n');
+ end
+
+ if rank(ctrb(Dyw)) < length(Dyw.A) || rank(obsv(Dyw)) < lenth(Dyw.A)
+ fprintf(' Scaled plant has Dyw that is not full rank.\n');
+ end
+
+ % Scaled pant
+ eigvals = eig(P_scaled.A);
+ stable_modes = 0;
+ for i = 1:n
+ if real(eigvals(i)) < 0
+ stable_modes = stable_modes +1;
+ end
+ end
+
+ % For higher number of states we get numerical problems
+ if n < 100
+ ctrb_modes = rank(ctrb(P_scaled));
+ obsv_modes = rank(obsv(P_scaled));
+
+ fprintf(' Scaled plant has %d modes: %d ctrb %d obsv %d stable %d unstable.\n', ...
+ n, ctrb_modes, obsv_modes, stable_modes, n - stable_modes);
+ else
+ fprintf(' Scaled plant has %d modes: %d stable %d unstable.\n', ...
+ n, stable_modes, n - stable_modes);
+ end
+
% Find controller using H-infinity
- [K, ~, gamma, ~] = hinfsyn(P_scaled, nmeas, nctrl, hinfopt);
+ if it > 1 && it ~= warmit
+ K_prev{it} = K;
+ gamma_prev{it} = gamma;
+ end
+
+ gamma_max=inf;
+ fprintf(' Running H-infinity with gamma in [%g, %g]\n', ...
+ gamma_min, gamma_max);
+ [K, ~, gamma, ~] = hinfsyn(P_scaled, nmeas, nctrl, [gamma_min, gamma_max], hinfopt);
+ gamma_max = 2 * gamma;
fprintf(' H-infinity synthesis gamma: %g\n', gamma);
if gamma == inf
error('Failed to synethesize H-infinity controller');
@@ -249,34 +346,44 @@ if do_musyn
N_frd = frd(N, omega);
M_frd = frd(M, omega);
- % Calculate upper bound D scaling
- fprintf(' Computing Performance SSV... ')
- [mu_bounds_rp, mu_info_rp] = mussv(N_frd, model.uncertain.BlockStructurePerf, 'U');
- fprintf(' Computing Stability SSV... ')
- [mu_bounds_rs, mu_info_rs] = mussv(M_frd, model.uncertain.BlockStructure, 'U');
+ % if warm start we do not need to recompute this
+ % as we are fiddling with D-scales
+ if it == warmit
+ fprintf(" Warm start, using SSVs from iteration %d\n", warmit);
+ else
+ % Calculate upper bound D scaling
+ fprintf(' Computing Performance SSV... ')
+ [mu_bounds_rp, mu_info_rp] = mussv(N_frd, model.uncertain.BlockStructurePerf, 'U');
+ fprintf(' Computing Stability SSV... ')
+ [mu_bounds_rs, mu_info_rs] = mussv(M_frd, model.uncertain.BlockStructure, 'fU');
+
+ mu_bounds_rp_prev{it} = mu_bounds_rp;
+ mu_bounds_rs_prev{it} = mu_bounds_rs;
+
+ % Plot SSVs
+ if do_plots
+ fprintf(' Plotting SSV mu\n');
+ figure(100); hold on;
+
+ bodemag(mu_bounds_rp(1,1));
+ mu_plot_legend = {mu_plot_legend{:}, sprintf('$\\mu_{P,%d}$', it)};
+
+ bodemag(mu_bounds_rs(1,1), 'k:');
+ mu_plot_legend = {mu_plot_legend{:}, sprintf('$\\mu_{S,%d}$', it)};
+
+ title('\bfseries $\mu_\Delta(\omega)$ for both Stability and Performance', ...
+ 'interpreter', 'latex');
+ legend(mu_plot_legend, 'interpreter', 'latex');
+ grid on;
+ drawnow;
+ end
+ end
mu_rp = norm(mu_bounds_rp(1,1), inf, 1e-6);
mu_rs = norm(mu_bounds_rs(1,1), inf, 1e-6);
fprintf(' SSV for Performance: %g, for Stability: %g\n', mu_rp, mu_rs);
- if do_plots
- fprintf(' Plotting SSV mu\n');
- figure(100); hold on;
-
- bodemag(mu_bounds_rp(1,1));
- mu_plot_legend = {mu_plot_legend{:}, sprintf('$\\mu_{P,%d}$', it)};
-
- bodemag(mu_bounds_rs(1,1), 'k:');
- mu_plot_legend = {mu_plot_legend{:}, sprintf('$\\mu_{S,%d}$', it)};
-
- title('\bfseries $\mu_\Delta(\omega)$ for both Stability and Performance', ...
- 'interpreter', 'latex');
- legend(mu_plot_legend, 'interpreter', 'latex');
- grid on;
- drawnow;
- end
-
% Are we done yet?
if mu_rp < 1
fprintf(' - Found robust controller that meets performance.\n');
@@ -320,7 +427,6 @@ if do_musyn
% for each block
for j = 1:4
- % for each in left and right
fprintf(' %s', D_names{j});
% tuned by hand?
@@ -356,14 +462,20 @@ if do_musyn
% at the first iteration). This is a heuristic to prevent
% adding too many states to the controller as it depends on
% the order of the D-scales.
- if abs(best_fit_err - fit_err) / best_fit_err > d_scales_improvement_p || best_fit_err == inf
+ improvement = abs(best_fit_err - fit_err);
+ improvement_p = improvement / best_fit_err;
+
+ if improvement_p > d_scales_improvement_p ...
+ || best_fit_err == inf
+
best_fit_deg = deg;
best_fit_err = fit_err;
D_fitted{j} = D_fit;
end
end
- if (fit_err / D_max_sv{j} < d_scales_max_err_p)
+ if fit_err / D_max_sv{j} < d_scales_max_err_p ...
+ || fit_err < d_scales_max_err
break;
end
fprintf('.');
@@ -374,6 +486,9 @@ if do_musyn
end
% Construct full matrices
+ D_left_prev{it} = D_left;
+ D_right_prev{it} = D_right;
+
D_left = blkdiag(D_fitted{1} * eye(4), ...
D_fitted{2} * eye(1), ...
D_fitted{3} * eye(12), ...
@@ -393,10 +508,12 @@ if do_musyn
sv_left = sigma(D_left, omega);
max_sv_left = max(max(sv_left));
+ d_fit_err = abs(max_sv_left_frd - max_sv_left);
fprintf(' Max SVD of D: %g, Dhat: %g\n', max_sv_left_frd, max_sv_left);
+ fprintf(' D scales fit abs. error: %g\n', d_fit_err)
fprintf(' D scales fit rel. error: %g %%\n', ...
- 100 * abs(max_sv_left_frd - max_sv_left) / max_sv_left_frd);
+ 100 * d_fit_err / max_sv_left_frd);
% Plot fitted D-scales
if do_plots