控制系统CAD实验.docVIP

实验内容 1 系统的传递函数为： 绘制出系统的根轨迹、Bode图和Nyquist图。 2 系统的开环传递函数为： 1） 2） 绘制系统的Bode图和Nyquist图，并讨论其稳定性以及计算系统的幅值裕度和相角裕度。 3 系统的闭环传递函数为 利用Routh判据、Hurwitz判据判断系统的稳定性。 4 系统的特征方程为 试利用Routh判据和Hurwitz判据判断系统的稳定性。 sys=tf([2,5,1],[1,2,3]) Transfer function: 2 s^2 + 5 s + 1 --------------- s^2 + 2 s + 3 rlocus(sys) [x,y]=ginput(2); p=x+i*y p = -2.8169 + 1.6351i -0.2222 - 0.0140i sys=tf([2,5,1],[1,2,3]) Transfer function: 2 s^2 + 5 s + 1 --------------- s^2 + 2 s + 3 rlocus(sys) num=[2,5,1];den=[1,2,3]; bode(num,den) num=[2,5,1];den=[1,2,3]; nyquist(num;den) ??? nyquist(num;den) | Error: Expression or statement is incorrect--possibly unbalanced (, {, or [. G=tf([2,5,1],[1,2,3]); nyquist(G) G=tf([1000,2000],[1,11,10,0]); nyquist(G) bode(G) axis(square) G_close=feedback(G,1); roots(G_close,den{1}) ??? Cell contents reference from a non-cell array object. G=tf([1000,2000],[1,11,10,0]); nyquist(G) ??? Invalid parameter/value pair arguments. ??? Error using == axes Error while evaluating line ButtonDownFcn. ??? Invalid parameter/value pair arguments. ??? Error using == axes Error while evaluating line ButtonDownFcn. ??? Invalid handle object. ??? Error while evaluating line ButtonDownFcn. bode(G) G=tf([1000,2000],[1,11,10,0]); roots(G.den{1}) ans = 0 -10 -1 G=tf([1000,2000],[1,11,10,0]); G_close=feedback(G,1); [Gm,Pm,Wcg,Wcp]=margin(G) Gm = Inf Pm = 16.1004 Wcg = Inf Wcp = 30.8643 den=[1,0.2,1.01]; function H=hurwitz(den) n=length(den)-1; for i=1:n, i1=floor(i/2); if i==i1*2, hsub1=den(1:2:n+1); i1=i1-1; else, hsub1=den(2:2:n+1); end l1=length(hsub1); H(i,:)=[zeros(1,i1),hsub1,zeros(1,n-i1-l1)]; end [key,sdet]=posdef(H) ??? function H=hurwitz(den) | Error: Function definitions are not permitted at the prompt or in scripts. den=[1,0.2,1.01]; function H=hurwitz(den) n=length(den)-1; for i=1:n, i1=floor(i/2); if i==i1*2, hsub1=den(1:2:n+1); i1=i1-1; else, hsub1=den(2:2:n+1); end l1=length(hsub1);