复杂结构的非线性检测

由于非线性系统的复杂性，现有的各种非线性检测方法都有局限性。从频域、幅域和时域三方面综合考察复杂结构的非线性表现，采用六种方法进行非线性检测，给出一个综合描述系统非线性程度的指标－非线性因子。鉴于非线性系统表现出的非线性强弱与系统所受的激励有直接的关系，将非线性因子定义为与激励的幅值特性和频率特性相关的系数指标。对几种典型非线性系统的仿真模型进行了检测，以验证非线性因子的有效性。

Nonlinearity Detection for Complex Structures

Each method for detecting an system's nonlinearity has it's localization because of the complexity of non-linear systems. Six methods for detecting the system's nonlinearity have been discussed in detail, and a synthetic indexfor detecting nonlinearity, with considering of the properties of the input signal and output signal in time - domain, fer-quancy - domain and their distribution functions is proposed in this paper. The system's nonlinearity index is defined asan index correlating with the statistical property of the exiting signal because the nonlinearity of an nonlinear system varieswith the exiting signal. Nurneric simulation for five equaons has been implemented in order to inspect the validity of theindex.