一种基于解析冗余关系的半定性故障隔离方法在航天器推进系统中的应用

摘要

针对航天器推进系统的时变特性以及随机因素给故障隔离带来的困难,提出了基于Z-检验分析和解析冗余关系相结合的半定性故障隔离方法.基于状态空间转换的思想,运用基于系统诊断键合图模型建立的解析冗余关系挖掘系统时不变的结构特征空间信息,并对解析冗余关系残差进行趋势分析获取时不变、具有残差变化方向的故障特征矩阵,针对存在随机因素对残差定性化的影响,利用了Z-检验分析对残差进行定性化获取观察特征,通过观测特征与故障特征的比较进行系统故障隔离.将该方法应用于推进系统的故障隔离中,结果证明了该方法能有效避免获取推进系统时变诊断准则以及来自系统建模和参数测量等随机因素的干扰,提高了推进系统故障隔离的鲁棒性.%Based on time-varying characters of spacecraft propulsion system and stochastic properties, the semi-qualitative fault isolation method which combines the Z-test and Analytical Redundancy Relations (ARRs) has been proposed. Firstly, based on the insight of state spatial alternation, it is achievable to mining time-invariant structural characters space using ARRs for Spacecraft Propulsion System which is built on the Diagnostic Bond Graph, and by the tendency analysis of the residuals of ARRs, the time-invariant fault signature matrix with change direction can be established. Secondly, the Z-test for robust qualitative residual generation to established observed signature against infection from multi-uncertainty is used, and then faults are isolated by comparison of observed signature and fault signature. Through the analysis of isolation results of a spacecraft propulsion system, it shows that the method is valid for overcoming the challenges from establishing time-varying diagnostic criteria and the jamming from stochasticity not only in the system model, but also in the measurements, which improves the robustness in fault isolation.