实验七 控制系统的时域分析方法钟Word文档下载推荐.docx
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(1)利用MATLAB模型链接函数求出系统闭环传递函数。
(2)利用step函数求单位阶跃响应
(3)利用gensig函数产生方波信号,利用lsim函数求方波响应。
3、已知系统传递函数:
(1)绘制系统阶跃响应曲线
(2)绘出离散化系统阶跃响应曲线,采样周期Ts=0.3s。
4、一个离散时间系统模型传递函数为,采样周期为0.1s,对其重新采样,采样周期为0.05s,求重新采样后的系统模型。
1
sys1=zpk([],[-1,-1/2,-1/3],10/6)
sys2=zpk([],[0,-1,-1/2],5)
sys3=zpk([],[0,0,-10,-5],500)
sys4=zpk([],[0,0,-10,-0.1],2)
[Gm1,Pm1,Wg1,Wp1]=margin(sys1)
[Gm2,Pm2,Wg2,Wp2]=margin(sys2)
[Gm3,Pm3,Wg3,Wp3]=margin(sys3)
[Gm4,Pm4,Wg4,Wp4]=margin(sys4)
(1)subplot(2,4,1),bode(sys1)
subplot(2,4,2),nyquist(sys1)
subplot(2,4,3),bode(sys2)
subplot(2,4,4),nyquist(sys2)
subplot(2,4,5),bode(sys3)
subplot(2,4,6),nyquist(sys3)
subplot(2,4,7),bode(sys4)
subplot(2,4,8),nyquist(sys4)
(2)figure
(1)
subplot(1,2,1),bode(sys1)
subplot(1,2,2),nyquist(sys1)
figure
(2)
subplot(1,2,1),bode(sys2)
subplot(1,2,2),nyquist(sys2)
figure(3)
subplot(1,2,1),bode(sys3)
subplot(1,2,2),nyquist(sys3)
figure(4)
subplot(1,2,1),bode(sys4)
subplot(1,2,2),nyquist(sys4)
Zero/pole/gain:
1.6667
------------------------
(s+1)(s+0.5)(s+0.3333)
5
---------------
s(s+1)(s+0.5)
500
----------------
s^2(s+10)(s+5)
2
------------------
s^2(s+10)(s+0.1)
Warning:
Theclosed-loopsystemisunstable.
>
InD:
\MATLAB6p5\toolbox\control\control\@lti\margin.matline89
Ind:
\MATLAB6p5\work\Untitled2.matline6
Gm1=
1.0000
Pm1=
0
Wg1=
1
Wp1=
\MATLAB6p5\work\Untitled2.matline7
Gm2=
0.1500
Pm2=
-40.4477
Wg2=
0.7071
Wp2=
1.5927
\MATLAB6p5\work\Untitled2.matline8
Gm3=
Inf
Pm3=
-46.0756
Wg3=
NaN
Wp3=
2.8848
\MATLAB6p5\work\Untitled2.matline9
Gm4=
Pm4=
-83.5723
Wg4=
Wp4=
0.5816
2
wn=90,xi=0.2
den=[1/wn^22*xi/wn10]
fork=1:
0.5:
40
num=[k]
sys=tf(num,den)
[Gm,Pm,Wcg,Wcp]=margin(sys)
if(Wcg>
=Wcp)
k
Gm
Pm
Wcg
Wcp
elseif(Wcg==Wcp)
elseif(Wcg<
end
3
g1=0.5
g2=tf([2,0],[2,1])
g3=zpk([],[0,-2],1);
g4=parallel(g1,-g2);
sys=g3*g4
step(sys,50)
[gm,pm,wcg,wcp]=margin(sys)
-0.5(s-0.5)
s(s+2)(s+0.5)
gm=
pm=
30.1549
wcg=
0.4082
wcp=
0.2481
0.2481
Gs=zpk([],[0,-1],10)
Gz1=c2d(Gs,0.01,'
zoh'
)
Gz2=c2d(Gs,1,'
figure
(1)
subplot(2,2,1),bode(Gz1)
subplot(2,2,2),nyquist(Gz1)
subplot(2,2,3),bode(Gz2)
subplot(2,2,4),nyquist(Gz2)
Gb1=feedback(Gz1,1,1)
Gb2=feedback(Gz2,1,2)
[num1,den1,Ts]=tfdata(Gb1,'
v'
[num2,den2,Ts]=tfdata(Gb2,'
subplot(1,2,1),dstep(num1,den1)
subplot(1,2,2),dstep(num2,den2)
10
-------
s(s+1)
Zero/pole/gain:
0.00049834(z+0.9967)
---------------------
(z-1)(z-0.99)
Samplingtime:
0.01
3.6788(z+0.7183)
-----------------
(z-1)(z-0.3679)
(z-1.027)(z-0.9634)
3.6788(z+0.7183)
--------------------
(z+0.2739)(z-3.481)
num1=
1.0e-003*00.49830.4967
den1=1.0000-1.99050.9896
Ts=0.0100
num2=03.67882.6424
den2=1.0000-3.2073-0.9533
Ts=1