2021-01-30 23:44

matlab求解含三个未知数的三个方程组成的方程组求不出正确解

s=tf('s')
Gop1=1.3/(1+s*2)*exp(-1.8*s)
GCL1=Gop1/(1+Gop1);
y1=step(GCL1,[0:0.01:50]);
figure(1)
step(GCL1,[0:0.01:50])

%从图中可以读出：
%pusai=（0.846-0.621）/（0.846-0.565）=0.8007;
%w=2*3.14/6.3;
%m=0.2567;

syms x y z real
w=2*3.14/6.3;
m=0.2567;
s=-0.2567*w+j*w;
Gs=x/(1+s*y)*exp(-z*s)
Im=imag(Gs)
Re=real(Gs)
eqns=[x/(1+x)==0.565,(x*sin((314*z)/315)*exp((4609615792312965*z)/18014398509481984)*((4609615792312965*y)/18014398509481984 - 1))/(((4609615792312965*y)/18014398509481984 - 1)^2 + (98596*y^2)/99225) - (314*x*y*cos((314*z)/315)*exp((4609615792312965*z)/18014398509481984))/(315*(((4609615792312965*y)/18014398509481984 - 1)^2 + (98596*y^2)/99225))== 0,- (314*x*y*sin((314*z)/315)*exp((4609615792312965*z)/18014398509481984))/(315*(((4609615792312965*y)/18014398509481984 - 1)^2 + (98596*y^2)/99225)) - (x*cos((314*z)/315)*exp((4609615792312965*z)/18014398509481984)*((4609615792312965*y)/18014398509481984 - 1))/(((4609615792312965*y)/18014398509481984 - 1)^2 + (98596*y^2)/99225)== -1];
xyz=vpasolve(eqns)
xyz.x
xyz.y
xyz.z

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