求助：怎样求一个传递函数的正弦响应

han1910

额，最近老师给个任务，要求我建立一个人机模型，然后再用matlab仿真，我本身对matlab认知基本为零，勉勉强强弄出了个阶跃响应和冲击响应的图，老师又要求把输入变成正弦波，我用lsim来编程，但是怎么也出不来结果，哪位大侠能指点一下，谢谢了:@Q
下面是我之前编的阶跃和冲击响应的程序。。。
s1=tf([0.1953 2.79],[0 1] ,'iodelay',0.3);
s2=tf([5.6224 6.1249],[1 7.5598 21.1766 0] ,'iodelay',0.1537);
s5=tf([0.1716 2.86],[0 1] ,'iodelay',0.3);
s6=tf([5.6224 6.1249],[1 7.5598 21.1766 0] ,'iodelay',0.1537);
s9=tf([0.3417 0.67],[0 1] ,'iodelay',0.3);
s10=tf([1.2206 4.0368],[1 1.2281 4.9747 0] ,'iodelay',0.1849);
s13=tf([0.2720 0.8],[0 1] ,'iodelay',0.3);
s14=tf([1.2206 4.0368],[1 1.2281 4.9747 0] ,'iodelay',0.1849);
s_temp1=series(s1,s2);
s_temp2=series(s5,s6);
s_temp3=series(s9,s10);
s_temp4=series(s13,s14);
set(s_temp1,'ioDelay',0);
set(s_temp2,'ioDelay',0);
set(s_temp3,'ioDelay',0);
set(s_temp4,'ioDelay',0);
s3=s_temp1/(1+s_temp1);
s7=s_temp2/(1+s_temp2);
s11=s_temp3/(1+s_temp3);
s15=s_temp4/(1+s_temp4);
s4=zpk(s3);
s8=zpk(s7);
s12=zpk(s11);
s16=zpk(s15);
set(s4,'ioDelay',0);
set(s8,'ioDelay',0);
set(s12,'ioDelay',0);
set(s16,'ioDelay',0);
figure;
subplot(2,2,1);
step(s4);
subplot(2,2,2);
step(s8);
subplot(2,2,3);
step(s12);
subplot(2,2,4);
step(s16);
figure;
subplot(2,2,1);
impulse(s4);
subplot(2,2,2);
impulse(s8);
subplot(2,2,3);
impulse(s12);
subplot(2,2,4);
impulse(s16);