系统方块图化简.pptx

1结构图三种基本形式结构图三种基本形式G1G2G2G1G1G2G1G2G1G2G1G1G21+串串 联联并并 联联反反 馈馈2结构图等效变换方法结构图等效变换方法1 三种典型结构可直接用公式三种典型结构可直接用公式2 相邻综合点可互换位置相邻综合点可互换位置3 相邻引出点可互换位置相邻引出点可互换位置注意事项：注意事项：1 不是不是典型结构典型结构不可不可直接用公式直接用公式2 引出点综合点引出点综合点相邻，相邻，不可不可互换位置互换位置3引出点移动引出点移动G1G2G3G4H3H2H1abG41G1G2G3G4H3H2H14G2H1G1G3综合点移动综合点移动向同类移动向同类移动G1G2G3H1G15G1G4H3G2G3H1作用分解作用分解H1H3G1G4G2G3H3H1Pk从从R(s)到到C(s)的第的第k条前向通路传递函数条前向通路传递函数梅逊公式介绍梅逊公式介绍 R-CC(s)R(s)=Pkk:称为系统特征式称为系统特征式=1-La+LbLc-LdLeLf+其中其中:所有单独所有单独回路增益回路增益回路增益回路增益之和之和LaLbLc所有两两互不接触回路增益乘积之和所有两两互不接触回路增益乘积之和LdLeLf所有三个互不接触回路增益乘积之和所有三个互不接触回路增益乘积之和k称为第称为第k条前向通路的余子式条前向通路的余子式求法求法:去掉第去掉第k条前向通路后所求的条前向通路后所求的7梅逊公式例梅逊公式例R-CR(s)C(s)L1=G1 H1L2=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)=?8L1L2=(G1H1)(-G 2 H2)L1=G1H1L2=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)梅逊公式求梅逊公式求C(s)(1-G1H1)9G1(s)G3(s)H1(s)G2(s)H3(s)H2(s)R(s)C(s)N(s)E(S)梅逊公式求梅逊公式求E(s)E(s)=1-G1H1+G2H2+G1G2H3-G1H1G2 H210G1(s)G3(s)H1(s)G2(s)H3(s)H2(s)R(s)C(s)N(s)E(S)梅逊公式求梅逊公式求E(s)E(s)=1-G1H1+G2H2+G1G2H3-G1H1G2 H2P1=11=1+G2H2(1+G2H2)P11=?+11G1(s)H1(s)H2(s)C(s)梅逊公式求梅逊公式求E(s)E(s)=1-G1H1+G2H2+G1G2H3-G1H1G2 H2(1+G2H2)G3(s)G2(s)H3(s)R(s)E(S)+12G1(s)H1(s)H2(s)C(s)梅逊公式求梅逊公式求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+G2H2)+13G1(s)H1(s)H2(s)C(s)梅逊公式求梅逊公式求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+四个单独回路，两个回路互不接触四个单独回路，两个回路互不接触e1abcdfghC(s)R(s)C(s)R(s)=1afbgch ehgf+afchabcded(1bg)前向通路两条前向通路两条信号流图信号流图15习题习题2-15(p72图图2-63)功放功放k3+15v-15v+15v-15v-k1-k2SMTG+30k20k10k10k10k10kuiuauoutu2u1位置随动系统原理图位置随动系统原理图16习题习题2-15方块图方块图K0=30v/330o=1/11(伏伏/度度)=5.21(伏伏/弧度弧度)K1=3 k2=2=1+Rf/Ri=1+20/10=33uautu2u1kts23S(Tms+1)km5.215.21k3uoui