基于Wiener过程的载人飞船热控泵寿命预测

Life Prediction for Circulation Pump of Manned Spacecraft Based on Wiener Process

载人飞船热控制循环泵(以下简称热控泵)属于高可靠性航天产品,在试验和使用中出现的寿命失效数据极少,采用传统的基于大样本寿命数据的可靠性分析方法难以满足工程要求。首先根据热控泵的试验数据和退化失效机理,确定关键性能参数为扬程和功率,采用带有正向漂移的Wiener过程拟合这两项性能的退化数据,建立性能退化轨道模型,并用随机加权方法解决模型参数估计时的小子样问题;根据退化失效的定义确定热控泵的寿命分布模型,与传统寿命分布模型不同的是,分布模型中的参数具有明确的物理含义;最后根据试验数据对热控泵的寿命进行预测,验证方法的有效性。

Reliability of eccentric pump of manned spacecraft is very high, life data is rare. It＇s difficult for traditional reliability analysis methods based on life data to meet the engineering requirements. Firstly, lift and power were proved to be two critical performance parameters for circulation pump. The Wiener process with drift was proposed to fit the degradation process of the two performance parameters. The random weighted method was proposed to solve the small sample problem confronted in estimating parameters for degradation paths. The life distribution model was obtained by random process theory. In the end, the life of circulation pump is predicted to illustrate the effectiveness of the model.