Research On Hierachical Modeling And Safety Analysis Technology Of EFVS Based On The Probabilistic Model Checker

Enhanced flight vision system can transfer the information to the pilot,which is superposed by real-time enhanced image out of the aircraft and the flight information,to improve the situation awareness and realize the low visibility operation.Analysis shows that because EFVS function fault or loss may cause failure conditions of classification I,II,or III,it is necessary to perform the quantitative system safety analysis.However,traditional method rely on expert experience,and the workload is heavy when the system is changed and iterated,it's difficult to meet the safety assessment requirements of complex airborne system.To solve these problems,a method of model-based safety analysis is proposed,so as to achieve the quantitative safety analysis and improve the efficiency of it.The research content includes:Firstly,based on the system design requirements of EFVS,its function and failure conditions of top layer are studied,and the system functional hazard analysis is completed.The nominal model of EFVS is established by analyzing its physical and logical architecture.Secondly,the failure information including failure mode,failure effect,failure rates and so on are analyzed to add to nominal model to generate the failure extended model.Thirdly,research on the translation rules,and translate the failure extended model to probabilistic checking model,to realize the quantitative analysis.Forthly,translate the quantitative analysis requirements to system quantitative attribute,and perform the model checking of typical failure conditions,to obtain the quantitative results and verify the design rationality of EFVS typical functional architecture.Finally,in order to prove the validity of the results,the traditional fault tree has been used to verify the calculation results,and the model-based method has been compared with traditional safety analysis method.The results show that the method used in this paper can realize the automatic quantitative analysis of complex system,the calculation results are valid and the efficiency of the safety analysis is improved.