说明：  本文考虑了一类参数不确定系统的鲁棒正实性, 给出了一个输出反馈系统具有鲁棒严格扩展正实性( ESPR) 的充分条件以及求反馈控制器的方法, 并利用该条件可估计出系统保持ESPR 的最大参数摄动范围
(In this paper we consider a class of uncertain system parameters are indeed robust, and gives a robust output feedback system expansion strictly positive realness (ESPR), as well as a sufficient condition for the method of feedback controller, and using the conditions ESPR systems to estimate the maximum range of parameter perturbations)