第二章 數(shù)學(xué)模型ppt課件

1、結(jié)構(gòu)圖三種基本形式結(jié)構(gòu)圖三種基本形式G1G2G2G1G1G2G1 G2G1 G2G1G1G21+串串 聯(lián)聯(lián)并并 聯(lián)聯(lián)反反 饋饋結(jié)構(gòu)圖等效變換方法結(jié)構(gòu)圖等效變換方法1 三種典型結(jié)構(gòu)可直接用公式三種典型結(jié)構(gòu)可直接用公式2 相鄰綜合點(diǎn)可互換位置相鄰綜合點(diǎn)可互換位置3 相鄰引出點(diǎn)可互換位置相鄰引出點(diǎn)可互換位置本卷須知：本卷須知：1 不是典型結(jié)構(gòu)不可直接用公式不是典型結(jié)構(gòu)不可直接用公式2 引出點(diǎn)綜合點(diǎn)相鄰，不可互換位置引出點(diǎn)綜合點(diǎn)相鄰，不可互換位置引出點(diǎn)移動(dòng)引出點(diǎn)移動(dòng)G1G2G3G4H3H2H1abG41G1G2G3G4H3H2H1G2H1G1G3綜合點(diǎn)移動(dòng)綜合點(diǎn)移動(dòng)向同類(lèi)移動(dòng)向同類(lèi)移動(dòng)G1G2G3H1

2、G1G1G4H3G2G3H1作用分解作用分解H1H3G1G4G2G3H3H1Pk從從R(s)到到C(s)的第的第k條前向通路傳遞函數(shù)條前向通路傳遞函數(shù)梅遜公式介紹梅遜公式介紹 R-CC(s)R(s)=Pkk:稱(chēng)為系統(tǒng)特征式稱(chēng)為系統(tǒng)特征式=1- La+ LbLc-LdLeLf+其中其中:所有單獨(dú)回路增益之和所有單獨(dú)回路增益之和LaLbLc所有兩兩互不接觸回路增益乘積之和所有兩兩互不接觸回路增益乘積之和LdLeLf所有三個(gè)互不接觸回路增益乘積之和所有三個(gè)互不接觸回路增益乘積之和k稱(chēng)為第稱(chēng)為第k條前向通路的余子式條前向通路的余子式求法求法: 去掉第去掉第k條前向通路后所求的條前向通路后所求的梅遜公式

3、例梅遜公式例R-CR(s)C(s)L1= G1 H1 L2= G3 H3L3= G1G2G3H3H1L4= G4G3L5 = G1G2G3L1L2= (G1H1) (G3H3) = G1G3H1H3L1L4=(G1H1)(G4G3)=G1G3G4H1P1=G1G2G31=1 G4(s) H1(s)H3(s) G1(s) G2(s) G3(s) G1(s) G2(s) G3(s) G1(s) G2(s) G3(s) G1(s) G2(s) G3(s)G4(s)G3(s)P2= G4G32=1+G1H1G4(s)G3(s)C(s)R(s)=?L1L2= (G1H1)(-G 2 H2 )L1= G1

4、H1L2= G2H2L3= G1G2H3G1(s)G3(s)H1(s)G2(s)H3(s)H2(s)R(s)C(s)N(s)E(S)C(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2G3G2+G1G2+ G2R(s) N(s)梅遜公式求梅遜公式求C(s)(1-G1H1)G1(s)G3(s)H1(s)G2(s)H3(s)H2(s)R(s)C(s)N(s)E(S)梅遜公式求梅遜公式求E(s)E(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2G1(s)G3(s)H1(s)G2(s)H3(s)H2(s)R(s)C(s)N(s)E(S)梅遜公式求梅遜公式求E(

5、s)E(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2P1=11=1+G2H2(1+G2H2)P11= ?+G1(s)H1(s)H2(s)C(s)梅遜公式求梅遜公式求E(s)E(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2(1+G2H2)G3(s)G2(s)H3(s)R(s)E(S)+G1(s)H1(s)H2(s)C(s)梅遜公式求梅遜公式求E(s)G3(s)G2(s)H3(s)R(s)E(S)P2= - G3G2H32= 1P22=?(- G3G2H3)R(s) E(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2(1+G2H

6、2)+G1(s)H1(s)H2(s)C(s)梅遜公式求梅遜公式求E(s)E(s)=1- G1H1+ G2H2+ G1G2H3-G1H1G2 H2(1+G2H2)G3(s)G2(s)H3(s)R(s)E(S)2= 1P22=?(- G3G2H3)R(s) N(s)P1= G2H31= 1(G2H3)+N(s)P2= - G3G2H3+四個(gè)單獨(dú)回路，兩個(gè)回路互不接觸四個(gè)單獨(dú)回路，兩個(gè)回路互不接觸e1abcdfghC(s)R(s)C(s)R(s)=1afbgch ehgf+afchabcded (1bg)前向通路兩條前向通路兩條信號(hào)流圖信號(hào)流圖習(xí)題習(xí)題2-15(p72圖圖2-63)功放功放k3+15v-15v+15v-15v-k1-k2SMTG+30k20k10k10k10k10kuiuauoutu2u1位置隨動(dòng)系統(tǒng)原理圖位置隨動(dòng)系統(tǒng)原理圖習(xí)題習(xí)題2-15方塊圖方塊圖K0=