2015/11/14 环节的频率响应一惯性环节 1 G(jo)= iTo+l 0 1/2 Re 0=00 45 l@=0" G(j o=1/T 1Gjo)川 U(o) () 0 ∠GUw) 1 1 To r2a2+1 =-arctan(To) T2o2+1 T2o2+1 0 1/T 00 School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 环节的频率响应一惯性环节（续） L(@)=-20lgTo+1 L(@)=-20lgVF2o2+1≈0 低频渐近线 0<<宁 0dB水平线 转折频率 (corner frequency/break frequency 1 L(@)=-201g @T 高频渐近线 02个 10 -20dB/dec斜线 0 渐近线吗 -10 -20dB/dec 20 实际幅频特性 I 30 School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 42015/11/14 4 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 1 ( ) 1 G j jT     ( ) arctan( ) G j T      2 2 | ( ) | 1 1 G j T     2 2 ( ) 1 1 U T     2 2 ( ) 1 V T T       环节的频率响应—惯性环节 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 2 2 L T ( ) 20lg 1      1 T   2 2 L T ( ) 20lg 1 0       L T ( ) 20lg     1 T   低频渐近线 1 (0 ) T    1 ( ) T     0dB 水平线 -20dB/dec 斜线 转折频率 （corner frequency/break frequency ） 1 T   高频渐近线 环节的频率响应—惯性环节（续）