用Matlab求最小拍系统时,会遇到把Go(S)*零阶保持器,然后Z变换求D(z).但是通常求出来的D(z)是长长一串,晕,还要判断是否有单位园外的零点呢...我的程序如下:syms sGs=(1-exp(-s))/s*2.1/s^2/(s+1.252)g=ilaplace(Gs)Gz=ztrans(g)Gz = -67971225/61328594*z/(z-1)+525/313*z/(z-1)^2-32812500/30664297*z/exp(-313/250)/(z/exp(-313/250)-1)-65625000/30664297*exp(313/500)*(1/exp(-313/500)*z^2-exp(-313/500)*z-exp(313/500)*z^2/exp(-313/500)^2+z/exp(-313/500)*exp(313/500)^2)/(2*z^2/exp(-313/500)^2-2*z-2*exp(313/500)*z/exp(-313/500)+2*exp(313/500)*exp(-313/500))+426825/195938-65625000/30664297*exp(313/500)*sinh(313/500) 但是我书上的答案是:0.265*z*(z+2.78)*(z+0.2)/(z-1)^2/(z-0.286)请问如何才能得到如此简洁的答案?~
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