基于子系统的非线性时变系统辨识方法

针对非线性时变系统提出一种基于子系统的辨识方法，用于时变多自由度（multiple degree-of-freedom，简称MDOF）系统中非线性的定位和估计，并且无需关于系统的先验知识。所提出的新方法提供一个连续时间模型，MDOF系统按照自由度被分解为不同的子系统。设计正交化算法和误差减小率（error reduction ratio, 简称ERR），可以确定子系统中质量和自由度之间的线性及非线性连接的所有信息。在辨识过程中，时变参数的时间表达式可以由新方法准确给出。用一个3自由度（degree-of-freedom, 简称DOF）集中质量系统和一个机械臂结构的辨识过程为例，对所提出的方法进行验证。由于简单性及高效性，此方法将在实际工程中取得广泛的应用。

New Identification Method for Nonlinear Time-Varying System Based on Subsystem

In this paper, a new identification method for nonlinear time-varying system based on subsystem is proposed. This new method can be used to locate and estimate the nonlinear characteristics of the multi-degree-of-freedom (MDOF) dynamic system without a priori knowledge regarding the system. A MDOF system can be partitioned into a number of different subsystems with a continuous-time model provided by the new method. All the information about the masses and linear or nonlinear connections in the subsystems can be determined with an orthogonality algorithm and an error reduction ratio (ERR) calculation. In this identification process, the time expressions of the time-varying parameters are also given. This new method is demonstrated by a 3 DOF lumped mass system and a mechanical arm structure. This new proposed identification method has a wide application prospect in practical engineering for its simplicity and efficiency.