Aviation BIT optimal method for reducing false alarm rate under gust environment

High false alarm rate is the major restrictive factors for the aviation built-in test (BIT) application in aircraft. This paper analyzes the environmental influence on the aviation BIT, and addresses that gust is the one of the principal reasons leading to false alarm from aviation BIT. Under the gust environment, the aero relative speed will be changed which changes the angle of incidence and lift force simultaneously. It inevitably makes the aviation BIT diagnosis data change and maybe cause false alarm in aviation BIT in some special situations. We gather the sample data influencing the BIT accuracy via the simulation experiment or actual test, and establish a decision network for the aviation BIT to confirm the influence degree under gust environment, which can comprehensively consider the change of various elements in the residual vector to distinguish the influence degree between the gust and real fault in the aircraft. This way, based on the original BIT diagnosis results and the output results of the decision network, the false alarm rate of aviation BIT can be effectively improved with weighting processing. The Monte Carlo simulation result shows the proposed aviation BIT optimal method is a good approach because it reduces the false alarm rate of aviation BIT under gust environment, and further improve the BIT diagnostic ability. The method will be useful in actual application.