www.gusucode.com > robust 案例源码程序 matlab代码 > robust/SampleResponsesOfUncertainControlSystemModelExample.m

    %% Sample Responses of Uncertain Control System Model
% This example illustrates how to sample the open and closed-loop response
% of an uncertain plant model for Monte Carlo analysis. 
%%
% Create two
% uncertain real parameters and an uncertain plant.

% Copyright 2015 The MathWorks, Inc.

gamma = ureal('gamma',4); 
tau = ureal('tau',.5,'Percentage',30); 
P = tf(gamma,[tau 1]); 
%%
% Create an integral controller based on the nominal values of plant uncertainties.
KI = 1/(2*tau.Nominal*gamma.Nominal); 
C = tf(KI,[1 0]); 
%%
% Now create an uncertain closed-loop system.
CLP = feedback(P*C,1); 
%%
% Sample the plant at 20 values, distributed uniformly about the |tau| and
% |gamma| parameter cube.
[Psample1D,Values1D] = usample(P,20); 
size(Psample1D) 
%%
% This sampling returns an array of 20 state-space models, each representing the
% closed-loop system within the uncertainty. 
%
% Now sample the plant at 10 values of |tau| and 15 values of |gamma|.
[Psample2D,Values2D] = usample(P,'tau',10,'gamma',15); 
size(Psample2D) 
%%
% Plot the step responses of the 1-D sampled plant.
subplot(2,1,1); 
step(Psample1D)
%%
% Evaluate the uncertain closed-loop model at the same values  using
% |usubs|, and plot the step response.
subplot(2,1,2); 
step(usubs(CLP,Values1D))