reinf2_11.m

离散控制系统设计的MATLAB 代码

%%%%%%%%%%% Reinforcement Problem 2.11 %%%%%%%%%%
%   Discrete-Time Control Problems using        %
%       MATLAB and the Control System Toolbox   %
%   by J.H. Chow, D.K. Frederick, & N.W. Chbat  %
%         Brooks/Cole Publishing Company        %
%                September 2002                 %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% --- Step response of a third-order system ---
%
clear
disp('Reinforcement Problem 2.11')
numG = [0.2 1.1 0.5]                     % create G(z)
denG = [1 0.7 0.5 0.1]                   % ...as TF object
G = tf(numG,denG,1)                      % ...with unit sampling period
numGstep = [numG 0]                      % add a zero at z=0 to G(z)
denGstep = conv(denG,[1 -1])             % add a pole at z=1 to G(z)
Gstep = tf(numGstep,denGstep,1)          % create zG(z)/(z-1) as TF object
dtime = [0:14];                          % define discrete time samples
[yi,ki] = impulse(Gstep,length(dtime));  % step response via impulse cmd
[ys,ks] = step(G,length(dtime));         % step response via step command
figure
title('Step Response for Reinforcement Problem 2.11')
subplot(2,1,1)
stem(ki,yi,'filled');grid                % plot impulse response of Gstep(z)
legend('via impulse cmd')
xlabel('Discrete time')
subplot(2,1,2)
stem(ks,ys,'o');grid     
legend('via step command')
xlabel('Discrete time')
disp('DC gain is:')
disp(dcgain(G))                          % DC gain of G(z)
%%%%%%%%%%