复合控制

321?G2GbcTTE(s)12s?(T1?T2?K2a)s?(1?K2b)s则?e(s)?； ?1??(s)??32R(s)1?G1G2TT12s?(T1?T2)s?(1?K1K2T2)s?K1K2欲使系统闭环系统响应速度输入R(s)?1/s3的稳态误差为0，即

32TT112s?(T1?T2?K2a)s?(1?K2b)s ess?limsE(s)?lims?e(s)R(s)?lims?3s?0s?0s?0TTs3?(T?T)s2?(1?KKT)s?KKs121212212，?e(s)应该包含R(s)?1/s3的全部极点。

?T1?T2?K2aT1?T2，则a??K2?1?K2b

b?1 K2