www.gusucode.com > robust 案例源码程序 matlab代码 > robust/ImproveWorstCaseGainResultsExample.m
%% Improve Worst-Case Perturbation % Specifying certain options for the structured-singular-value computation % that underlies the worst-gain computation can yield better results in % some cases. For example, consider a sample plant and controller. %% load(fullfile(matlabroot,'examples','robust','wcgExampleData.mat')) %% % This command loads |gPlant|, a MIMO plant with 10 outputs, 8 inputs, and % 11 uncertain elements. It also loads |Kmu|, a state-space controller % model. Form a closed-loop system with these models, and examine the % worst-case gain. CL = lft(gPlant,Kmu); [wcg,wcu] = wcgain(CL); wcg %% % There is a large difference between the lower and upper bounds on the % worst-case gain. To get a better estimate of the actual worst-case gain, % increase the number of restarts that |wcgain| uses when the worst-case % perturbation |wcu| and associated lower bound for the worst-case gain. % Doing so can result in a tighter lower bound. This option does not affect % the upper-bound calculation. opt = wcOptions('MussvOptions','m3'); [wcg,wcu] = wcgain(CL,opt); wcg %% % The difference between the lower bound and upper bound on the worst-case % gain is much smaller. The critical frequency is different as well.