实验六实验六 四四 A=0,1,0,0;0,0,1,0;0,0,0,1;-65.5,-213.8,-204.2,-54; B=0;0;0;1; C=1562,1875,0,0; D=0; sys=ss(A,B,C,D); bode(sys);-150-100-50050Magnitude (dB)10-210-1100101102103-270-180-900Phase (deg)Bode DiagramFrequency (rad/sec)六六 1 b=1; a=1,1; freqz(b,a);00.10.20.30.40.50.60.70.80.91050100Normalized Frequency ( rad/sample)Phase (degrees)00.10.20.30.40.50.60.70.80.91-200204060Normalized Frequency ( rad/sample)Magnitude (dB) clear; num=1,0; den=1,1; dbode(num,den,1);-1000100200300400Magnitude (dB)10-110010104590Phase (deg)Bode DiagramFrequency (rad/sec)2 w=0:0.05:20; num=2,0; den=1,sqrt(2),1; h=freqs(num,den,w); mag=abs(h); phase=angle(h); subplot(2,1,1) plot(w,mag); title(幅频特性) subplot(2,1,2); plot(w,phase); title(相频特性)02468101214161820-2-1012幅 幅 幅 幅0246810121416182000.511.5幅 幅 幅 幅clear; num=2,0; den=1,sqrt(2),1; sys=tf(num,den); bode(sys);-50-40-30-20-10010Magnitude (dB)10-210-1100101102-90-4504590Phase (deg)Bode DiagramFrequency (rad/sec)3 clear; b=1,2,1; a=1,0,0.61; freqz(b,a);10-210-1100-200-1000100Normalized Frequency ( rad/sample)Phase (degrees)00.10.20.30.40.50.60.70.80.91-100-50050Normalized Frequency ( rad/sample)Magnitude (dB) clear; b=1,2,1; a=1,0,0.61; dbode(b,a,1);-300-200-1000100Magnitude (dB)10-210-1100101-180-135-90-450Phase (deg)Bode DiagramFrequency (rad/sec)4 clear; z=1;2; p=-1;-2; k=3; num,den=zp2tf(z,p,k); w=0:0.05:20; h=freqs(num,den,w); mag=abs(h); phase=angle(h); subplot(2,1,1) plot(w,mag);title(幅频特性) subplot(2,1,2);plot(w,phase); title(相频特性)02468101214161820333幅 幅 幅 幅02468101214161820-4-2024幅 幅 幅 幅 clear; z=1;2; p=-1;-2; k=3; num,den=zp2tf(z,p,k); sys=tf(num,den); bode(sys);9.54249.54249.54249.54249.54249.54249.5424Magnitude (dB)10-210-1100101102090180270360Phase (deg)Bode DiagramFrequency (rad/sec)实验十一实验十一 一一 1 t=0.5;N=20;fs=N/t;T=1/fs; n = -N:1:N; xn=(sin(10*pi*n*T)+eps)./(10*pi*n*T+eps); X = fft(xn,4096); f=0:4095/4096/T; plot(f,abs(X)051015202530354000.511.522.533.544.52 clear; t=0.2;N=20;fs=N/t;T=1/fs; n = -N:1:N; xn=(sin(10*pi*n*T)+eps)./(10*pi*n*T+eps); X = fft(xn,4096); f=0:4095/4096/T; plot(f,abs(X)01020304050607080901000246810123 clear; t=0.01;N=20;fs=N/t;T=1/fs; n = -N:1:N; xn=(sin(10*pi*n*T)+eps)./(10*pi*n*T+eps); X = fft(xn,4096); f=0:4095/4096/T; plot(f,abs(X)0200400600800100012001400160018002000051015202530354045实验十四实验十四 一一 正弦信号阶跃信号三角波二二 123