实验三系统频率特性曲线的绘制及系统

1、自动控制原理实践报告实验三系统频率特性曲线的绘制及系统分析熟悉利用计算机绘制系统 伯德图、乃奎斯特曲线的方法，并利用所绘制图 形分析系统性能。一、实验目的1 熟练掌握使用MATLAB件绘制Bode图及Nyquist曲线的方法；2 进一步加深对Bode图及Nyquist曲线的了解；3利用所绘制Bode图及Nyquist曲线分析系统性能。二、主要实验设备及仪器实验设备：每人一台计算机奔腾系列以上计算机，配置硬盘2G内存64M。实验软件：WINDOWS作系统（WINDOWS5 或 WINDOWS）。），并安装 MATLAB 语言编程环境。三、实验内容已知系统开环传递函数分别为如下形式,(1)G(s)

2、50(s 5)(s 2)(2)G(s) 口250s(s 5)( s 15)(3)G(s)s 102s(2s s 1)(4)G(s)二8s(2s 1)(0.2s 1)(5)G(s)2s 2s 1s3 - 0.2s2 s 1(6)4(0.5s+1)s(2s 1)(0.125s)20.05s 1)1 绘制其Nyquist曲线和Bode图，记录或拷贝所绘制系统的各种图形;1、程序代码：num=50;den=con v(1 5,1 2);bode( nu m,de n)Bode DiagramIDDacodnrrngaM-1012lyeatesaB10-210101010310Frequency (ra

3、d/sec)num=50;den=con v(1 5,1 2);nyq uist (nu m,de n)321Nyquist Diagram0-1-2-30 12Real Axis345.PXA vymraa 卩-4-12、程序代码：num=250;den=conv(con v(1 0,1 5),1 15); bode( nu m,de n)0Bode Diagram-50-100-150-90-135-180-225-270-1010110Freque ncy (rad/sec)2101050eau.knQa M)a§ esaB310num=250;den=conv(con v(1

4、 0,1 5),1 15);nyq uist (nu m,de n)PXA vranrga 卩on*-System: sysReal: -0.132Imag: -0.0124Frequency (rad/sec): -10.3Nyquist Diagram-0.9- 0.8-0.7-0.6-0.5-0.4-0.3-0.2-0.1Real Axis3、程序代码：num=1 10;den=co nv(1 0,2 1 1);bode( nu m,de n)100Bode Diagram)oo o o o o5 5 0 5 9- 1 .1 - kodveanrrnaa M801702-odiodiFr

5、eque ncy (rad/sec)num=1 10;den=co nv(1 0,2 1 1);nyq uist (nu m,de n)Nyquist Diagram50100150ooo oo 5002PXA VFanpQa p-5-15-1020-50-220-4、程序代码：num=8;den=co nv(con v(1 0,2 1),0.2 1);bode( nu m,de n)Bode Diagram'I3U RQ nMb DU3 MmeaesathFreque ncy (rad/sec)num=8;den=con v(co nv(1 0,2 1),0.2 1);nyq uis

6、t (nu m,de n)Nyquist Diagram250-2-48di 顶505-500500050- -2 11 112 2- - - -Krx A VT anr9a5、程序代码：num=1 2 1; den=1 0.2 1 1; bode( nu m,de n)100-10-20-30-40-90-180-270-360XDDUVeanMkHaa MlyeavesaB-21Bode Diagram-1010101010210Freque ncy (rad/sec)num=1 2 1;den=1 0.2 1 1;nyq uist (nu m,de n)SIXA uanT9a HLL&l

7、t;s''-/- /ritt1-ir11.5Nyquist Diagram-1.5-1- 0.500.53 2-2Real Axis-26、num=2 4;den=conv(conv(1 0,2 1),0.015625 0.05 1);bode( nu m,de n)100=一一 _一"""-rrr r F ir r r Fr r r r r r rlrt r r r r r Frrr ir f r t rBode Diagram50o o o o5 5 0 9- 1 - )Bac §u Fn Qa Mlysucesa.B3580270-

8、w2-o1OFrequency (rad/sec)num=2 4;den=conv(conv(1 0,2 1),0.015625 0.05 1);nyq uist (nu m,de n)Nyquist DiagramRKXA vranraa n0050-500-6-5-4-3-2-10Real Axis2利用所绘制出的Nyquist曲线及Bode图对系统的性能进行分析：（1）利用以上任意一种方法绘制的图形判断系统的稳定性；由Nyquist曲线判断系统的稳定性，Z=P-2NL1、P=0, N=0,则系统稳定。2、P=0, N=0,则系统稳定。3、P=0, N=0,则系统稳定。4、P=0, N=0

9、,则系统稳定。5、P=0, N=0,则系统稳定。6、P=0, N=0,则系统稳定。（2）如果系统稳定,则进一步分析系统的相对稳定性： 在Bode图上求出系统的增益裕度Kg （用分贝数表示）和相角裕度，及其所对应的相位穿越频率和增益穿越频率。1、20Bode Diagram System: sysf f fFrequency (rad/sec): 6.11Magnitude (dB): -0.17IDDflr40-System: sysFrequency (rad/sec): 0.0104Phase (deg): -1.1460-80o-45-90-13510-2-110System: sysF

10、requency (rad/sec): 403Magnitude (dB): -70.2System: sysFrequency (rad/sec): 6.03Phase (deg): -122System: sysFrequency (rad/sec): 401Phase (deg): -1790 110 10Frequency (rad/sec)210310增益裕度Kg : 70.2相角裕度：581010System: sysFrequency (rad/sec): 8.83Phase (deg): -181.)DDQCeau.knaa MLuedTesanp101010Frequency

11、 (rad/sec)增益裕度Kg : 17相角裕度：48IDDOCeau-knaa MBode Diagram:匸 System: sysFrequency (rad/sec): 0.489Magnitude (dB): 29.1System: sysFrequency (rad/sec): 1.78Magnitude (dB): 0.11-90XLUedTesanp-135-180System: sysSystem: sysFrequency (rad/sec): 0.728Phase (deg): -1801 _ _JFrequency (rad/sec): 0.0119Phase (de

12、g): -90.7-225-270-210-110System: sysFrequeqcy1(rad/sec): 2.52 代 Phase (deg): -244Frequency (rad/sec)010310增益裕度Kg : -29.1相角裕度：-64相位穿越频率：0.728增益穿越频率：1.78.)DDQCeau.knaa M100500-50-100System: sysFrequency (rad/sec): 1.52Magnitude (dB): 3.95System: sysFrequency (rad/sec): 1.9Magnitude (dB): 0.00136r r f

13、1rt f r r B r rfrt r il r t r c IFrLuedTesanpF- -B1111System: sysFrequency (rad/sec): 1.9 Phase (deg): -186 System: sysFrequency (rad/sec): 1.57Phase (deg): -180rrf r rr r r firr r a- fr r r rrrrr r r t IF!?rr r r it r-90-135-180-225-270-2-10110101010210Frequency (rad/sec)增益裕度Kg : -3.95相角裕度：-6相位穿越频率

14、：1.57增益穿越频率：1.9System: sysFrequency (rad/sec): 1.11Magnitude (dB):BOde DIDDOCeau-knaa MLuedTesanpSystem: sysFrequency (rad/sec): 1.83Magnitude (dB): 0.0774agram-101O-W-2O30-o O4 9- -80TO-2System: sysFrequency (rad/sec): 1.45Phase (deg): -180System: sysFrequency (rad/sec): 2.37Phase (deg): -13510-210

15、10Frequency (rad/sec)10210增益裕度Kg : 8.97相角裕度：4550System: sysFrequency (rad/sec): 1.61Magnitude (dB): -0.0886-50System: sysPhase (deg): -128-135Frequency (rad/sec): 0.0106Phase (deg): -90.9-180-225一System: sysFrequency (rad/sec): 7.69Phase (deg): -180-270itFE r r r r r 1*rE*r r ir i! r r.rrr F ir -100 L_ -90 .tr t System、sys匸Frequency (rad/sec): 1.67LuedTesanpSystem: sysFrequency (rad/sec): 6.46Magnitude (dB): -9.3710-2-110010Frequency (rad/sec)110