Research On Testability Allocation Method Of Avionics System For Upgrading And Modification

The upgrade and modification of avionics system will involve safety testing,and how to allocate reasonable testability indexes is one of the key issues that must be solved in safety testing.A reasonable testability index allocation(TIA)scheme is of great significance for improving the fault diagnosis and isolation capability of the avionics system,improving system safety,reducing maintenance costs and so on.Aiming at TIA in the process of upgrading and modification of the avionics system,a systematic research is carried out,and the specific contents are as follows.Firstly,the hierarchical division method of avionics system is studied to clarify the functional structure of the system and cross-linking relationship among the units.According to the relevant standards and the classification of test maintenance activities,combined with the structural characteristics of the avionics system,on the basis of the top-down principle,the avionics system is divided into system,subsystem,line replaceable unit,shop replaceable unit and sub-shop replaceable unit,which clarify the structural levels of the TIA.Then,the factors affecting the security of testability allocation are analyzed.Aiming at reducing the test cost of the avionics system after upgrading,the cost function model of the system is established with the requirements for index allocation values as the constraints,and the TIA problem of the avionics system is converted into a nonlinear programming(NLP)problem for multi-objective optimization values.For this NLP problem,the Sequential Quadratic Programming(SQP)algorithm and the hybrid Particle Swarm Optimization(PSO)and SQP algorithm are proposed respectively.The results of the optimized allocation and the results obtained by the traditional mature allocation method are compared and analyzed.The results show that the proposed optimal allocation method is reasonable and feasible.Finally,the Avionics System Testability Allocation Modeling and Analysis Platform is designed and developed,including the overall framework design of the platform,design of six subroutines of user login,basic information input of the unit,total requirement index setting,influence factors and weight coefficients setting,testability allocation and analysis report display,the joint programming of platform and MATLAB,and application of SQLite database.The platform provides an auxiliary tool for solving the TIA problem of avionics system.