基于贝叶斯网络的汽车起重机液压系统的可靠性评估

Reliability Assessment of Hydraulic Systems in Automobile Crane Based on Bayesian Networks

为评估汽车起重机液压系统的可靠性,首先结合故障树分析法(FTA)、贝叶斯网络(BN)构建液压系统故障树,然后映射成BN,再利用其在多态性和不确定性方面的优势,应用桶排除法,对系统进行可靠性评估。在给出底事件的发生概率后,通过正向推理,得到顶事件发生的概率为0.191 016。针对模型进行多态性和不确定性修正后,得到的顶事件概率为0.228 073,相对提高19.4%。最后利用反向推理,找出系统的薄弱环节并给出改正措施,为更全面高效的可靠性评估提出一种新方法。

For the purpose of assessing the reliability of hydraulic systems in automobile crane,combined with fault tree analysis and BN,the assessment model of the hydraulic systems failure was established firstly.Secondly,mapped into a BN,and assessing the reliability of the systems by using the advantages of BN in terms of the multi-state variables and uncertainty relations and combining with the Bucket Elimination.After the probability of events being given,the top event probability of 0.191 016 was gotten by forward reasoning.However,after correcting the model in terms of the multi-state variables and uncertainty relations,the top event probability of 0.228 073 was gotten,relatively increased by 19.4%.By the backward reasoning,the weaknesses of the systems was found out and the corrective measures were given.The study has put forward a new method for reliability assessment in a more comprehensive and effective manner.