动态系统故障的混杂传播特征及建模方法

摘要

动态系统的故障传播过程是由离散事件、连续特性及其相互作用共同驱动的，具有显著的混杂特征，为故障规律认知与建模带来了较大的难度。现有研究将故障视为离散随机事件，分析由单元随机故障发生到系统失效的离散故障过程，却忽略了连续特性对故障传播的影响，本质上是对故障混杂传播的工程简化处理，不能真实地描述动态系统的故障规律。首先在分析动态系统故障规律的基础上，给出了离散与连续双维度下的动态系统故障混杂传播的定义，分析了其混杂影响要素以及混杂传播特征；其次，为了完整准确描述混杂特征，借鉴混杂理论在描述离散事件与连续参数相互作用方面的优势，提出了基于随机混杂自动机（stochastic hybrid automa-ta，SHA）的故障混杂传播建模方法；最后通过对某温度控制系统的故障混杂传播过程进行建模和仿真，验证了动态系统故障传播过程中的混杂特征，以及建模方法的可行性。%The failure propagation in dynamic systems is driven by discrete component fault events,continu-ous processes as well as their interactions.This hybrid feature of the fault propagation brings about the difficul-ty in fault cognition and modeling.Existing researches regard faults just as discrete events.Thus they only fo-cus on analyzing how the discrete system failures are caused by random component failures.However,the con-tinuous processes in fault propagation have always been ignored for the sake of simplifications in engineering, which leads to the inaccuracy of the description of dynamic system failures.This paper defines the hybrid failure propagation within two dimensions for the dynamic system,and analyzes its hybrid factors and propagation fea-tures.For accurate description of these hybrid features,a hybrid failure propagation modeling method is pro-posed based on the hybrid theory which is used to model the interaction of discrete events and continuous proces-ses.The proposed method is applied to a temperature control system.The simulation results show the hybrid feature of the failure propagation,as well as the feasibility of the presented modeling method.