清空筛选条件
清空筛选条件

Could't get right result laplace,ilaplace,PD

2 次查看（过去 30 天）
Emrah Duatepe
Emrah Duatepe 2019-7-27
评论： Star Strider 2019-7-31
hi friends,
I am trying to plot laplace with PD ,the plot I have got is wrong according to book ,where am I making mistake.Automatic Control Systems(Benjamin C. Kuo)
syms Kp Kd s t
K = 181.17;
Ku = 5;
Tu = 0.5;
Kp = 1;
Kd = 0.002;
Ki = 0;
%Fs=sym(((1.5E7*K)/(s^3 + 3408.3*s^2 + 1213086*s + 1.5E7*K))*(Kp + Kd*s));
Fs=sym( ((1.5E7*K)*(Kp + Kd*s )) / ((s+3293.3)*(s+57.49+j*906.6)*(s+57.49-j*906.6)) )
ft=ilaplace(Fs,s,t);
t = 0:0.001:0.3;
f = subs(ft);
plot(t,f)

请先登录，再回答此问题。

采纳的回答

Star Strider
Star Strider 2019-7-27
I have no idea what the plot is supposed to look like. However depending on your MATLAB release/version, you may have to use the expand function first, then the partfrac function, before you call ilaplace:
Fs=sym( ((1.5E7*K)*(Kp + Kd*s )) / ((s+3293.3)*(s+57.49+j*906.6)*(s+57.49-j*906.6)) )
Fs = expand(Fs)
Fspf = partfrac(Fs)
ft=ilaplace(Fspf,s,t);
t = 0:0.001:0.3;
f = subs(ft);
plot(t,f)
See if that does what you want.
The partial fraction expansion is:
and the time domain expression is:
  2 个评论
Star Strider
Star Strider 2019-7-31
Emrah Duatepe’s Answer moved here:
That was what I need ,but thank you to help
a=1
Kp = 0.11112;
Kd = 0.00034198;
Ki = 4.3789;
t0=0.3;
ts=0.0001;
t=[0:ts:t0];
s = tf('s');
Fs = (2.718E9/(s*(s+400.26)*(s+3008)))*(Kp + Kd*(s/(a*s+1)) + Ki/s)
H = 1;
FB = feedback(Fs,H,-1);
%Giriş sinyali oluşturuluyor(Kare dalga)
u0 = t>= 0;
ut03 = (t-t0/3) >= 0;
u2t03 = (t - 2*t0/3) >= 0;
m1 = u0 - ut03;
m2 = -2*(ut03 - u2t03);
m = m1 + m2;
noise = 0.1*randn(1,length(t));
u=u0 + noise;
lsim(FB,u,t)
Star Strider
Star Strider 2019-7-31
My pleasure.
If my Answer helped you solve your problem, please Accept it!

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Calculus 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by