则
GB?z?z?21?e?2z?21?e?2D?z?????2z1?e?1HGC?z??1?GB?z??HGC?z?1?z?1e?2?z?21?e?21?z?1e?2?z?21?e?2?1?11?ze???????1?ze??1?e???1?e??1?ze??1?e?z??1?0.3679z??1?0.1353???1?0.3679??1?0.1353z??1?0.1353?z??1?1?2?1?1?2?2?2?1?1?2??????????1.3680?0.5033z?1?1?0.1353z?1?0.8647z?2U?z?又D?z?? E?z?则U?z??0.1353z?1U?z??0.8647z?2U?z??1.3680E?z??0.5033z?1E?z?
上式反变换到时域，则可得到
u?k??1.3680e?k??0.5033e?k?1??0.1353u?k?1??0.8647u?k?2?
14、图所示的计算机串级控制系统中，已知采样周期为
a0?a1z?1?a2z?2T，且有D1(z)?1?z?1,
b0?b1z?1D2(z)?1?z?1串级控制算法。
，其中：a0、a1、a2、b0、b1是使D1(z)和D2(z)能够实现的常数，试写出计算机
题2图
