A sufficient condition to guarantee closedloopstabilization is provided, and the change of performance from projection error is estimated.
证明了降阶控制器保证系统稳定的一个充分条件，并给出了投影误差引起的系统性能变化的范围估计。
2
Closedloop feedback adopts PID control rule to insure the stabilization of magnification times.
闭环反馈采用PID这种最广泛使用的控制规律，以保证放大倍数的稳定。
3
Simultaneous stabilization with closed-loop poles is discussed in this paper. Necessary and sufficient conditions, as well as the controller design algorithms are given.