确定根轨迹与虚轴交点,判断系统稳定时增益K的取值范围
代码如下
allmargin产生一个结构。GainMargin表示增益,GMFrequency表示对应的频率
a =
GainMargin: [15.6153 67.5209 163.5431]
GMFrequency: [1.2132 2.1510 3.7551]
PhaseMargin: 77.3823
PMFrequency: 0.1659
DelayMargin: 8.1404
DMFrequency: 0.1659
Stable: 1
k =
15.6153 67.5209 163.5431
wg =
<
代码如下
num=[1 2 4];
den1=conv([1 0],[1 4]);den2=conv([1 6],[1 1.4 1]);
den=conv(den1,den2);
w=tf(num,den);
%求根轨迹与虚轴的交点信息
a=allmargin(w)
%交点增益值
k=a.GainMargin
%交点频率
wg=a.GMFrequency
rlocus(w)
axis([-8 2 -5 5]);
allmargin产生一个结构。GainMargin表示增益,GMFrequency表示对应的频率
a =
GainMargin: [15.6153 67.5209 163.5431]
GMFrequency: [1.2132 2.1510 3.7551]
PhaseMargin: 77.3823
PMFrequency: 0.1659
DelayMargin: 8.1404
DMFrequency: 0.1659
Stable: 1
k =
15.6153 67.5209 163.5431
wg =
<