The authors begin with some intrinsic characteristics of the closed-loop system, e.g., overshoot and undershoot, on account of open-loop unstable poles and zeros.Then, a controller is designed.

• 通过讨论分析开环系统的不稳定极点和零点给闭环系统带来的超调和下冲等一些必然属性，设计了二级倒立摆的控制器。