基于证据推理和置信规则库的装备寿命评估

针对航天产品试验样本少,寿命评估难的特点,结合产品在研制阶段多种工作环境的失效数据,提出了一种基于证据推理(evidential reasoning,ER)和置信规则库(belief-rule-base,BRB)进行装备寿命评估的新方法.首先,分析了模型的合理性并使用多维BRB模型将多种环境下的寿命数据折合为标准工作环境下的寿命数据,然后通过ER算法将折合后数据和实际工作环境数据进行融合.其次,详细说明了BRB--ER模型的推理过程和寿命评估的步骤.最后,采用某航天产品的失效数据对该方法进行了验证,并用已有的产品寿命的固定值进行BRB的参数更新.研究结果表明,在专家知识准确合理时,该模型能够准确地评估产品寿命,并可根据已有的产品的固定寿命进行训练,建立更加准确的寿命预测模型.

Life assessment approach of equipment based on belief-rule-base and evidential reasoning

It is difficult to assess the life of equipment by using few sample data. As such, based on the belief-rule-base (BRB) and evidential reasoning (ER) approach, a new BRB-ER model is proposed, which uses effectively few failure data and expert knowledge. Firstly, the rationality of employing the model is analyzed, where BRB is used to calculate the environmental factor between one environment and the standard working environment by using few life data and expert knowledge, and the ER approach is adopted to aggregate the data under various environments to assess the life of products. Secondly, the process of reasoning by using BRB-ER model and steps of assessing the life of the equipment is expounded. Finally, a case study is carried out to illustrate the ability and the training process of BRB-ER model. This study proves that the model is effective for the life assessment by using expert knowledge and update parameters for a better model.