一、引言模型简化是高阶系统分析与设计中的一个重要问题.近年来,许多国内外学者提出了不少模型降阶方法.按系统各模态对输出的能量贡献来确定主导特征根的降阶方法山就是其中之一,文献[2]将其推广到多变量的情形.这一方法计算简单,可保证降阶模型 I. INTRODUCTION Model simplification is an important issue in high-level system analysis and design. In recent years, many domestic and foreign scholars have proposed a number of model reduction methods. According to the contribution of each mode of the system to the output energy to determine the dominant eigenvalues Reduced-order method Shan is one of them, and literature [2] generalizes it to multivariable case. This method is simple and can guarantee the reduced order model