控制系统仿真（MATLAB版）（九）

>> syms K T

>> assume(T<2&T>0)

>> assume(K>0)

>> isAlways((2+T)*(K+1)-2*T*K>0)

ans =

  logical

   1

>> assume(T>2)

>> eqn = (2+T)*(K+1)-2*T*K;

>> K = solve(eqn,K)

 

K =

 

(T + 2)/(T - 2)

 

T = (2+eps):0.01:10;

K = (T + 2)./(T - 2);

plot(T,K)

axis([0 10 0 450])

hold on

plot([2,2],[0,450],'--')

 gtext('目标区域')

xlable('T')

ylabel('K')

title('K-T双参数可行域')