上海交通大学：《系统模型、分析与控制 Modeling、Analysis and Control》课程教学资源[13]Lecture72-frequency characteristic plots 频率特性图

2015/11/14 环节的频率响应一一 阶微分环节 G(j@)=jw@+1 Im 0=00 0 =0 Re arctgor IG(j@)川 ∠G(jo) V() 0 =√F2o2+i arctan(ro) U(o)=1 =t0 0 lh 00 School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 环节的频率响应一一阶微分环节（续） G(j@)=jt@+1 30 L(@)=201gv202+1 (gp)/)7 20 10 实际幅频特性 20dB/dec (@)arctan(ro) 渐近线 9 是 45 转折频率 0" 0.1/T 1/T 10T (radlsec) School of Mechanical Engineering ME369-lecture 7.2 Shanghal Jiao Tong University Fall 2015 6

2015/11/14 6 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University ( ) arctan( ) G j   2 2  | ( ) | 1 G j     G j j ( ) 1     V ( )    U( ) 1   环节的频率响应—一阶微分环节 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University    ( ) arctan( )  2 2 L( ) 20lg 1      G j j ( ) 1     环节的频率响应—一阶微分环节（续）

2015/11/14 环节的频率响应一一阶微分环节（续） 惯性环节 1 G(jo)= 阶微分环节 G(j@)=jt@+1 jT@+1 30 (p)/o)7 20dB/dee 20 际幅须特性 10 实际城特性 20ddee∠ 30 渐近线 0 转折率 10 (radisec) 互为倒数的环节 -对数幅频特性曲线关于零分贝线对称 -一相频特性曲线关于零度线对称 School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 环节的频率响应一振荡环节 1 G(j0)= T2(jo2+2T5(jo)+1 )0 (0=0) Gjo)=1∠0 1 G(jo)--J2G =0.3 -0.7 0.2 (0=o) Gj@)=0∠-180 0=0 0.1 2 -1 Re School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 7

2015/11/14 7 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 惯性环节 一阶微分环节 G j j ( ) 1     1 ( ) 1 G j jT     互为倒数的环节 ----- 对数幅频特性曲线关于零分贝线对称 ----- 相频特性曲线关于零度线对称 环节的频率响应—一阶微分环节（续） BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 2 2 1 ( ) ( ) 2 ( ) 1 G j T j T j        ( )   ( 0)   G j ( ) 1 0    1 ( ) n T     1 ( ) 2 G j j     G j ( ) 0 180     环节的频率响应—振荡环节

2015/11/14 环节的频率响应一振荡环节（续） L(o)=-20lgV1-T2o2)2+(25To)2 (@)=-arctan 25T0 1-72） E为常数 (0<宁 L(o)≈0 低频渐近线 0<0<宁 p(o)=0° 0dB水平线 1 (0= =0)p)=-g'25）)=-90 0 转折频率 (@>） L(@)=-201g(OT)=-401goT 高频渐近线 (片<<0) p(o)=-180° -40dB/dec斜线 School of Mechanical Engineering ME369-lecture 7.2 Shanghal Jiao Tong University Fall 2015 环节的频率响应一振荡环节（续） 00 0.1 =0.3 =0.2 =0.5 0 -10 渐近线 40dB/dec 00 =0.7 2=1.0 0 40 135 -180 0.1 1 10 @/0n School of Mechanical Engineering ME369-lecture 7.2 Shanghai Jiao Tong University Fall 2015 8

2015/11/14 8 BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 为常数 2 2 2 2 L T T ( ) 20lg (1 ) (2 )         1 ( ) T   L( ) 0   2 L T T ( ) 20lg( ) 40lg        1 ( ) T   1 ( ) n T     ) T 1 (0   ) T 1 (    低频渐近线 0dB 水平线 -40dB/dec 斜线 转折频率 高频渐近线 2 2 2 ( ) arctan( ) 1 T T          ()  0 1 2 ( ) ( ) 90 0          tg  ()  180 环节的频率响应—振荡环节（续） BE315-Lecture 7.2 Fall 2011 ME369-lecture 7.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 环节的频率响应—振荡环节（续）