Aircraft GCU Build-in-test Functionresearch And Fault Analysis

The Built-in Test(BIT) is an intergral capability of the mission equipment which provides an on-board,automated test capability to detect,diagnose,or isolate system failtures.It is an effiective approach to improve testability and maintainability of a complex system.However,with the increasing requirements of fault detection and the maintenance time,many problems of this conventional BIT technique are manifested,such as notorious False Alarm(FA),Cannot Duplicate(CND) and Retest OK(RTOK),which have some strong effects on the readiness of cicvil aircraft,especially Power system(MEAEPS) must be significantly higher than conventional aircrafts.Futhermore,the MEA requires that more effective and efficient testing and fault diagnosis techniques be developed to improve the reliability of the EPS.So it is very important to study the rule of BIT design for the new generation GCU in order to improve the capability of MEA.The main contents of the paper included as follows:1. All faults which may happen are analyzed and summarized in the dissertation.It is established for all the faults’ mode and Effect Analysis.On the basis of that,according to the selecting principle of fault detecting points,the points set which are fit.2. The design based on DSP aircraft generator control unit principle mimic,it has all of the typical power supply controller circuit module,and it will be able to realize the BIT of three different ways of working detection:the electricity BIT detection,continuous BIT detection,and manual BIT detection.3. Based on circuit hardware description language simulation platform of fault,the fault injection verify the proposed a BIT of test methods of efficiency and feasibility.The Paper introduced the design of generator each module controller BIT of hardware and implementation.In the specific design processing,it has designed various realization and carried on the detailed analysis and demonstration way to all methods,finally chose the way to realize is the optimization from the view of engineering. In addition to the function of the controller should have been realized,but also the design carry on from hardware and software two aspects for the system reliability and the electromagnetic compatibility.The design of the controller hardware development platform have perfect function,well performance and commonality,and it will be helpful to the design of the GCU BIT in the future,also to other airborne electronic equipments.