www.gusucode.com > robust 案例源码程序 matlab代码 > robust/SingleInputSingleOutputSISOLoopSensitivitiesExample.m
%% Single Input, Single Output (SISO) Loop Sensitivities % Consider PI controller for a dominantly 1st-order plant, with the % closed-loop bandwidth of 2.5 rads/sec. Since the problem is SISO, all % gains are the same at input and output. % Copyright 2015 The MathWorks, Inc. gamma = 2; tau = 1.5; taufast = 0.1; P = tf(gamma,[tau 1])*tf(1,[taufast 1]); tauclp = 0.4; xiclp = 0.8; wnclp = 1/(tauclp*xiclp); KP = (2*xiclp*wnclp*tau - 1)/gamma; KI = wnclp^2*tau/gamma; C = tf([KP KI],[1 0]); %% % Form the closed-loop (and open-loop) systems with |loopsens|, and plot Bode % plots using the gains at the plant input. loops = loopsens(P,C); bode(loops.Si,'r',loops.Ti,'b',loops.Li,'g') %% % Finally, compare the open-loop plant gain to the closed-loop value of % |PSi|. bodemag(P,'r',loops.PSi,'b')