考虑环境干扰的液体运载火箭结构安全性评估方法

A safety assessment method for a liquid launch rocket based on the belief rule base with environmental disturbance

液体运载火箭作为卫星运载的重要平台,对其结构安全性进行准确的评估极其重要.本文针对液体运载火箭实际工作过程中监测数据易受到噪声干扰的问题,基于置信规则库(belief rule base,BRB)提出了一种考虑环境干扰的液体运载火箭结构安全性评估方法.首先,通过分析火箭监测数据的特征,提出了一种基于距离的监测指标不确定度求取方法,通过指标不确定度来反映噪声对于监测数据的影响程度;然后,针对目前置信规则库模型中仅考虑了定性知识的不确定,无法处理监测数据不确定的问题,提出了一种考虑指标不确定度的输入数据匹配度转换方法,监测数据中包含不确定性信息的大小通过剩余匹配度表示;最后,基于BRB构建了液体运载火箭安全性评估模型,对存在不确定性的监测数据进行融合,得到液体运载火箭的安全性状态.通过实验室搭建的基于无线传感网络的运载火箭监测平台验证了所提方法的有效性.

Liquid launch rockets are used as one of the most important platforms for carrying satellites.Thus,its structural safety must be accurately assessed.To address the environmental disturbance for observation data in engineering practice,a new safety assessment method is proposed in this paper with belief rule base(BRB)and environmental disturbance consideration.First,the characteristic analysis is conducted for the rocket,and an uncertainty calculation method based on distance for observation index is provided.The uncertainty index is used to present the disturbance degree of observation data from environmental noise.Second,only the uncertainty of qualitative knowledge is considered in current studies of the BRB model,and the uncertainty in quantitative data cannot be addressed.Thus,a new calculation method for matching degrees of input data is developed,where the uncertainty of the observation data can be represented using the residual matching degree.Finally,to integrate the uncertainty of the observation data,a safety assessment model for the liquid launch rocket is developed based on the BRB model.A case study based on a rocket monitoring platform with a wireless sensor network is evaluated to demonstrate the efficiency of the proposed method.