www.gusucode.com > control 案例程序 matlab源码代码 > control/TimeDelayApproximationInContinuousTimeOpenLoopModelExample.m
%% Time-Delay Approximation in Continuous-Time Open-Loop Model % %% Create model of open-loop system % Copyright 2015 The MathWorks, Inc. s = tf('s'); P = exp(-2.6*s)/(s^2+0.9*s+1); %% Compute first-order Pade approximation Pnd1 = pade(P,1) %% Compare frequency responses h = bodeoptions; h.PhaseMatching = 'on'; bodeplot(P,'-b',Pnd1,'-.r',{0.1,10},h) legend('Exact delay','First-Order Pade','Location','SouthWest') %% Increase approximation order Pnd3 = pade(P,3); %% Compare new frequency responses bodeplot(P,'-b',Pnd3,'-.r',Pnd1,':k',{0.1 10},h) legend('Exact delay','Third-Order Pade','First-Order Pade',... 'Location','SouthWest') %% Compare time domain responses stepplot(P,'-b',Pnd3,'-.r',Pnd1,':k') legend('Exact delay','Third-Order Pade','First-Order Pade',... 'Location','Southeast')