试验三系统频率特性曲线的绘制及系统分析要点

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 Diagramo-240-60-Frequency (rad/sec)IDDacodnrrngaMnum=50;den=c

3、on v(1 5,1 2);nyq uist (nu m,de n)4 321o1di.PXA vymraa 卩2、程序代码：num=250;den=conv(con v(1 0,1 5),1 15); bode( nu m,de n)50eau.knQa M-150-900Bode Diagram-50-100)a§ esaB-270-135-180-225-101210101010310Freque ncy (rad/sec)num=250;den=conv(con v(1 0,1 5),1 15);nyq uist (nu m,de n)Nyquist DiagramPXA v

4、ranrga 卩System: sysReal: -0.132Imag: -0.0124Frequency (rad/sec): -10.3-0.9- 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)001kodveanrrnaa Mo0050-90Bode Diagram50o702-2-11001011021010531801522-3Freque ncy (rad/sec)num=1 10;den=co nv(1 0,2 1 1);nyq uist (

5、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)100Bode Diagram50ooFreque ncy (rad/sec)num=8;den=con v(co nv(1 0,2 1),0.2 1);nyq uist (nu m,de n)Real AxisNyquist Diagram250-2-48di 顶505-500500050- -2 11 112 2- - -

6、 -Krx A VT anr9a5、程序代码：num=1 2 1; den=1 0.2 1 1; bode( nu m,de n)10DDUVeanMLnaa MBode DiagramolyeovesaB801702-360 L-210-110010110210Freque ncy (rad/sec)Real Axisnum=1 2 1;den=1 0.2 1 1;nyq uist (nu m,de n)Nyquist Diagram23-2-2SIXA uanT9a H6、num=2 4;den=conv(conv(1 0,2 1),0.015625 0.05 1);bode( nu m,

7、de n)Bode Diagram100 i)Bac §u Fn 03 M- - -lysucesa.BFrequency (rad/sec)num=2 4;den=conv(conv(1 0,2 1),0.015625 0.05 1);nyq uist (nu m,de n)RKXA vranraa nNyquist Diagram-5-4-3Real Axis-2 -1 00050-5002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

8、,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,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: sys Frequency (rad/sec): 6.11Magnitude (dB): -0.17IDDflr40-l9eores3BSystem: sys d/sec): 6.03 e (deg): -1

9、2260-80O45-35 dSystem: sysFrequency (rad/sec): 401Phase (deg): -179I I LII川 )-210-1100 110 10Frequency (rad/sec)210增益裕度Kg : 70.2相角裕度：5811-System: sysFrequency (rad/sec): 403Magnitude (dB): -70.2310相位穿越频率：401增益穿越频率：6.113、Bode Diagram System: sysFrequency (rad/sec): 2.84500H-100-150Magnitude (dB): -0.

10、00944.)DDQCeau.knaa MJ,-50System: sysFrequency (rad/sec): 9.37Magnitude (dB): -17System: sys101010Frequency (rad/sec)1010System: sysFrequency (rad/sec): 8.83Phase (deg): -181LuedTesanp增益裕度Kg : 17相角裕度：48相位穿越频率：8.83增益穿越频率：2.845、Bode Diagram10050System: sysFrequency (rad/sec): 0.489Magnitude (dB): 29.1

11、.)DDQCeau.knaa M-50System: sysFrequency (rad/sec): 1.78Magnitude (dB): 0.117、-100-150-90LuedTesanp-135-180-225-270-210System: sysFrequency (rad/sec): 0.0119Phase (deg): -90.7-110System: sysFrequency (rad/sec): 0.728Phase (deg): -180System: sysFrequeqcy1(rad/sec): 2.52 代2 Phase (deg): -244Frequency (

12、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：1.78Bode Diagram相位穿越频率：1.57增益穿越频率：1.99、System: sysFrequency (rad/sec): 1.52Magnitude (dB): 3.95System: sysFrequency (rad/sec): 1.9Magnitude (dB): 0.00136 System: sysFrequency (rad/sec): 1.9 Phase (deg): -186-System: sysFrequency (rad/sec): 1.57P

13、hase (deg): -180-50O 1003 任180225IDDOCeau-knaa MLuedTesanp-270-2-10 1 210 10 10 10 10Frequency (rad/sec)增益裕度Kg : -3.95相角裕度：-6System: sysFrequency (rad/sec): 1.11agramMagnitude (dB):E8)de D10DDOT'eauaa M_ _ -System: sysFrequency (rad/sec): 1.83Magnitude (dB): 0.0774-3ISystem: sys |Frequency (rad/

14、sec): 1.45Phase (deg): -180LuedTesanpSystem: sysFrequency (rad/sec): 2.37Phase (deg): -13580TO-210-2-110010Frequency (rad/sec)110210增益裕度Kg : 8.97相角裕度：45相位穿越频率：1.45增益穿越频率：1.83#、Bode Diagram0050IDDOCeau-knaa M50-00-90System: sysFrequency (rad/sec): 1.61Magnitude (dB): -0.0886System: sysFrequency (rad/sec): 6.46Magnitude (dB): -9.37LuedTesanp3580522-10-2System: sysFrequency (rad/sec): 0.0106Phase (deg): -90.9System: sysFrequency (rad/sec): 7.69Phase (deg): -180.i i System，sysFrequency (rad/sec): 1.67Phase (deg): -128-110010Frequency (rad/sec)110210增益裕度Kg : 9.3