Comparing the Responses
Plot the responses of the design. The redesign of the control system using both
approaches yields similar controllers. This example shows the effects of the
computational delay and discretization. These effects reduce the stability margins of the
system, but when you properly model a control system you can achieve the desired
closed-loop behavior.
plot(T1,Y1,'k',T3,Y3,'b',Td,Yd,'m',Tc,Yc,'r')
xlabel('Time (sec.)')
ylabel('Engine Speed Response');
h = legend('cont. compensator (orig)','disc. compensator (orig)', ...
'disc. compensator (disc. redesign)',...
'disc. compensator (cont. redesign)',...
'Location','SouthEast');
grid
bdclose('scdspeed_contcomp')
bdclose('scdspeed_compdelay')
Modeling Computational Delay and Sampling Effects