再求闲环脉冲传递函数G(z)0.632zF(z)=1 + G(z)z2 - 0.736z + 0.3680.632z2C(2)=F (2)R(2)= - 1.7362 +1.104z- 0.368C(z) = 0.632z 1 + 1.097z, 2 + 1.207z 3 +1.014 z 4 +0.96z 5 + 0.968 z 6 + 0.99 z 7 + ...c*(t) = 0.632 (t T) + 1.097 (t 2T) + 1.207 (t3T)+1.014 (t 4T) + 0.96 (t 5T) + 0.968 ( t□ 6T) +60.99 (t 7T) + ...KV
再求闭环脉冲传递函数 C(z) = 0.632z 1 + 1.097z 2 + 1.207z 3 +1.014 z 4 + 0.96z 5 + 0.968 z 6 + 0.99 z 7 + . c*(t) = 0.632 ( t T) + 1.097 ( t 2T) + 1.207 ( t 3T) + 1.014 ( t 4T) + 0.96 ( t 5T) + 0.968 ( t 6T) + 0.99 ( t 7T) + . 6
+c*(t0 T 2T 3T4T 5T6Tc*(t) = 0.632 (t T) + 1.097 (t 2T) + 1.207~ (t口3T)+1.014~(t 4T)+0.96(t5T)+0.968(t6T,±20.7%297% 72. ,=3(),= 5(5)p福连续二阶系统: ,% =16.3% , t,= 2.42(s), t,= 3.6(s)t,= 5.3(s)
0 T 2T 3T 4T 5T 6T c*(t ) t 1 c*(t) = 0.632 ( t T) + 1.097 ( t 2T) + 1.207 ( t 3T) + 1.014 ( t 4T) + 0.96 ( t 5T) + 0.968 ( t 6T) + 0.99 ( t 7T) + . p% =20.7% t r = 2(s) t p = 3(s) t s = 5(s) 连续二阶系统: p% =16.3%，t r = 2.42(s)，t p = 3.6(s)， t s = 5.3(s) 7
例8-26在例8-45中，增加零阶保持器，采样系统如图示， T=1(s), r(t)=1(t), 试分析系统的性能指标。ctZOHs(s+1)解：求开环脉冲传递数él-e-Ts uDe5ZG(z) = Z 1-Ise-(s+1)1(s+1)0.368z. + 0.264(z. -1)(z - 0.368)8
解：求开环脉冲传递函数 例8-26 在例8-45中，增加零阶保持器，采样系统 如图示，T＝1(s)，r(t)=1(t)，试分析系统的性能指标。 r(t) c(t) + - 1 s(s+1) ZOH 8
再求闲环脉冲传递函数G(z)0.368z + 0.264F(z)=1 + G(z)z~ - z + 0.6320.368z2 + 0.264zC(z) =F(z)R(z) =73 - 2z2 +1.632z - 0.632C(z) = 0.368z 1 + z 2 + 1.4z 3 +1.4z 4 + 1.147z. 5 +0.895z 6 + 0.802z 7 + 0.868z 8 + ...c*(t) = 0.368 (t T) + (t 2T) + 1.4 (t 3T) + 1.4(t 4T)+1.147 (t 5T) + 0.895 (t 6T) + 0.802 (t7T)9+ 0.868 (t 8T) + 0.993 (t 9T) +
再求闭环脉冲传递函数 C(z) = 0.368z 1 + z 2 + 1.4z 3 +1.4z 4 + 1.147z 5 + 0.895z 6 + 0.802z 7 + 0.868z 8 + . c*(t) = 0.368 ( t T) + ( t 2T) + 1.4 ( t 3T) + 1.4 ( t 4T) + 1.147 ( t 5T) + 0.895 ( t 6T) + 0.802 ( t 7T) + 0.868 ( t 8T) + 0.993 ( t 9T) + . 9
R0T2T3T4T5T7T6Tc*(t) = 0.368 (t T) + (t 2T) + 1.4 (t 3T) + 1.4(t 4T)+1.147 (t 5T) + 0.895 (t 6T) + 0.802 (t□7T)p%748% (t) +0.9(t9(..10
0 T 2T 3T 4T 5T 6T 7T c*(t ) 1 t c*(t) = 0.368 ( t T) + ( t 2T) + 1.4 ( t 3T) + 1.4 ( t 4T) + 1.147 ( t 5T) + 0.895 ( t 6T) + 0.802 ( t 7T) + 0.868 ( t 8T) + 0.993 ( t 9T) + . p% =40% t r = 2(s) t p = 4(s) t s = 12(s) 10