dkds.m

来自「华东理工大学自动化系《控制系统分析、设计和应用》教材配套程序实例,有关说明： 」· M 代码 · 共 13 行

function [k,s]=dkds(G)
% 确定系统G根轨迹在实轴上的分离点和会合点s和相应的增益k

% Copyright 2001-2002 ECUST. 
%   $Revision: 1.2 $  $Date: 2002/02/04 16:45:18 $

G=tf(G);num=G.num{1};den=G.den{1};dt=get(G,'inputdelay');syms nums dens;
a1=conv(den,polyder(num));a2=conv(num,polyder(den));
a11=([zeros(1,length(a2)-length(a1)),a1]-a2);a12=dt*conv(num,den);
ss=roots([zeros(1,length(a12)-length(a11)),a11]-a12);k=[];s=[];
for i=1:length(ss);nums=poly2sym(num,'s');dens=poly2sym(den,'s');
kk(i)=-subs(nums/dens,'s',ss(i));if kk(i) > 0 ,k=[k,kk(i)];s=[s,ss(i)];end;
end;