计算机仿真实验指导书

locus(num3,den3);Рtitle('(3)')Р; Р2.熟悉和掌握MATLAB有关控制系统根轨迹法的函数命令及分析方法。设单位反馈控制系统的开环传递函数为,应用MATLAB命令编写相应M文件,要求:①绘制闭环根轨迹;Р②确定系统的临界稳定开环增益;Р③确定与系统临界阻尼比相应的开环增益。Р①Рnum=1;Рden=conv(conv([1,0],[0.01,1]),[0.02,1]); Рrlocus(num,den);Р[k,poles]=rlocfind(num,den)Р②РSelect a point in the graphics windowРselected_point =Рk =149.6960Рpoles =Р 1.0e+002 *Р -1.4994 Р -0.0003 + 0.7065iР -0.0003 - 0.7065iР由上面可以看出:当K<149.6960时,系统稳定;Р 当K>149.6960时,系统不稳定;Р③Рnum1=149;Рden1=conv(conv([1,0],[0.01,1]),[0.02,1]); Р[num,den]=feedback(num1,den1,1,1);Рfigure(1)Рimpulse(num,den,100);Рnum2=150;Рden2=conv(conv([1,0],[0.01,1]),[0.02,1]); Р[num,den]=feedback(num2,den2,1,1);Рfigure(2)Рimpulse(num,den,10);Рnum3=151;Рden3=conv(conv([1,0],[0.01,1]),[0.02,1]); Р[num,den]=feedback(num3,den3,1,1);Рfigure(3)Рimpulse(num,den,100);РK=149