Based on the multivariable analog of civcle criterion, an observer is designed to estimate the system states and hence the dynamical equations satisfied by the estimation error are derived first.

• 基于多变量的圆判据设计观测器来估计系统的状态，进而给出了观测误差满足的动态方程，然后利用积分反推方法，构造性地设计出了输出反馈镇定控制器。